Exposure apparatus, movable body drive system, pattern formation apparatus, exposure method, and device manufacturing method

ABSTRACT

While a wafer stage moves linearly in a Y-axis direction, surface position information of a wafer surface at a plurality of detection points set at a predetermined interval in an X-axis direction is detected by a multipoint AF system, and by a plurality of alignment systems arranged in a line along the X-axis direction, marks at different positions on the wafer are each detected, and a part of a chipped shot of the wafer is exposed by a periphery edge exposure system. This allows throughput to be improved when compared with the case when detection operation of the marks, detection operation of the surface position information (focus information), and periphery edge exposure operation are performed independently.

CROSS REFERENCE TO RELATED APPLICATIONS

This non-provisional application is a continuation of non-provisionalapplication Ser. No. 15/599,785 filed May 19, 2017, which in turn is acontinuation of non-provisional application Ser. No. 14/466,408 filedAug. 22, 2014 and issued on Jun. 27, 2017 as U.S. Pat. No. 9,690,205,which in turn is a division of non-provisional application Ser. No.12/344,659 filed Dec. 29, 2008 and issued on Jan. 5, 2016 as U.S. Pat.No. 9,229,333, which claims the benefit of Provisional Application No.61/006,812 filed Jan. 31, 2008, Provisional Application No. 61/006,813filed Jan. 31, 2008, and Provisional Application No. 61/071,899 filedMay 23, 2008, the disclosures of which are hereby incorporated herein byreference in their entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to exposure apparatus, movable body drivesystems, pattern formation apparatus, exposure methods, and devicemanufacturing methods, and more particularly to an exposure apparatusused in a lithography process when electronic devices such as asemiconductor device a liquid crystal display device and the like areproduced, a movable body drive system which can be suitably used in theexposure apparatus, and measures a position of a movable body using anencoder system, a pattern formation apparatus equipped with the movablebody drive system, an exposure method used in a lithography process, anda device manufacturing method which uses the exposure apparatus or theexposure method.

Description of the Background Art

Conventionally, in a lithography process for manufacturing electrondevices (microdevices) such as semiconductor devices (such as integratedcircuits) and liquid crystal display devices, exposure apparatuses suchas a projection exposure apparatus by a step-and-repeat method so-calledstepper) and a projection exposure apparatus by a step-and-scan method(a so-called scanning stepper (which is also called a scanner) aremainly used.

When exposure of a wafer is performed with these kinds of exposureapparatus, a section (an area that cannot be used as a product (chip))which is not exposed is produced in the periphery of the wafer. However,the existence of such a section (an area) which is not exposed becomes aproblem in a chemical mechanical processing (CMP) process which isapplied to planarize the surface of a wafer on which a pattern isformed. Therefore, also in the past, of shot areas (hereinafter referredto as a “periphery shot”) that do not completely fit in the effectiveexposure area in the periphery portion of the wafer, a periphery edgeexposure in which the portion which cannot be used as a device isexposed has been performed (e.g., refer to Kokai (Japanese PatentUnexamined Application Publication) No. 2006-278820)).

However, in the case of performing the periphery edge exposureseparately from the exposure of transferring and forming a reticlepattern on a wafer, throughput declines due to the time required for theperiphery edge exposure.

Meanwhile, as an approach for improving the throughput, variousproposals are made on a twin wafer stage type exposure apparatus whichemploys a method where a plurality of wafer stages holding a wafer, suchas for example, two wafer stages, are arranged, and concurrentprocessing of different operations is performed on the two stages.Recently, a proposal has been made on a twin wafer stage type exposureapparatus which employs a liquid immersion method (for example, refer toU.S. Pat. No. 7,161,659).

However, the device rule (practical minimum line width) is becomingfiner, and with this, an overlay performance with higher precision isbecoming required in the exposure apparatus. Because of this, a furtherincrease is expected in the number of sample shots in Enhanced GlobalAlignment (EGA), which is the mainstream in wafer alignment, which maycause a decrease in the throughput even if the exposure apparatus is thetwin wafer stage type exposure apparatus.

Further, in exposure apparatus such as steppers, scanners and the like,for example, position measurement of a stage holding a wafer wasgenerally measured using a laser interferometer. However, due to finerpatterns which accompany higher integration of semiconductor devices,requirements in performance is becoming tighter, and short-termvariation of measurement values which is caused by air fluctuation whichoccurs due to the influence of temperature fluctuation and/ortemperature gradient of the atmosphere on the beam path of the laserinterferometer can no longer be ignored.

Therefore, recently, an encoder with a high resolution which isimpervious to air fluctuation when compared with an interferometer hasbegun to gather attention, and inventors have proposed an exposureapparatus which uses the encoder in position measurement of a waferstage and the like (for example, refer to the pamphlet of InternationalPublication 2007/097379 and the like).

However, in the case of arranging a scale (a grating) on the uppersurface of the wafer stage as in the exposure apparatus according to theembodiment of the pamphlet of International Publication 2007/097379described above, there were hardly any degrees of freedom in theplacement which made it difficult to create a layout, because there weremany encoder heads.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provideda first exposure apparatus that exposes an object with an exposure beam,the apparatus comprising: a movable body which holds the object andmoves along a predetermined plane including a first axis and a secondaxis orthogonal to each other; a measurement system which is placed awayfrom an exposure position where the exposure is performed in a directionparallel to the first axis that performs a predetermined measurement ofthe object; and a periphery edge exposure system, which is placed awayfrom the measurement system in a direction parallel to the first axisthat exposes at least some periphery shot areas of the object.

According to this apparatus, at least some shot areas in the peripheryof the object are exposed by the periphery edge exposure system whilethe movable body holding the object is moved along a direction parallelto the first axis within the predetermined plane. This allows theperiphery edge exposure to be performed in parallel with the movement ofthe object (movable body) which is moved from the measurement systemtoward the exposure position, or with the movement of the object(movable body) in an opposite direction (for example, movement of themovable body from the exposure position to the exchange position of theobject), which hardly reduces the throughput compared with when theperiphery edge exposure is performed independently.

According to a second aspect of the present invention, there is provideda second exposure apparatus that exposes an object with an exposurebeam, the apparatus comprising: a movable body which holds the objectand is movable within a predetermined plane including a first axis and asecond axis orthogonal to each other; and a periphery edge exposuresystem which is arranged between an exposure position where the exposureis performed and an exchange position of the object placed away from theexposure position in a direction parallel to the first axis, and exposesat least a part of a periphery area which is different from an area onthe object where the exposure is performed, whereby at least a part ofan exposure operation of the periphery area is performed in parallelwith a movement operation of the movable body from one of the exposureposition and the exchange position to the other.

According to this apparatus, at least a part of the exposure operationof the periphery areas by the periphery edge exposure system isperformed, in parallel with a movement operation of the movable bodyfrom one of the exposure position and the exchange position to theother. Therefore, unlike the case when the periphery edge exposure isperformed independently, the throughput is hardly reduced.

According to a third aspect of the present invention, there is provideda third exposure apparatus that exposes an object with an energy beamand forms a pattern on the object, the apparatus comprising: a firstmovable body which holds an object and moves within a predeterminedplane which includes a first axis and a second axis orthogonal to eachother; a second movable body which holds an object and movesindependently from the first movable body within the plane; a markdetection system which has a plurality of detection areas whosepositions are different in a direction parallel to the second axis, anddetects a mark on the object mounted on each of the first and secondmovable bodies; and a controller which detects a plurality of differentmarks of an object held by the other one of the first and second movablebodies with the mark detection system and measures positionalinformation of the marks, while moving the other one of the movablebodies in a direction parallel to the first axis, in parallel with anexposure performed of an object held by one of the first and secondmovable bodies.

According to this apparatus, the controller detects a plurality ofdifferent marks of an object held by the other one of the first andsecond movable bodies with the mark detection system and measurespositional information of the marks, while moving the other one of themovable bodies in a direction parallel to the first axis, in parallelwith an exposure performed of an object held by one of the first andsecond movable bodies. Therefore, it becomes possible to detect thepositional information of a plurality of, such as for example, all ofthe marks on the object held by the other movable body while the othermovable body is being moved in the first axis direction from theposition (for example, in the vicinity of the position where exchange ofthe object held by the movable body is performed) in the vicinity of theplurality of detection areas of the mark detection system to theexposure position, in parallel with exposure of the object held by oneof the movable bodies. As a consequence, it becomes possible to achieveimprovement of the throughput as well as improvement of the overlayaccuracy.

According to a fourth aspect of the present invention, there is provideda fourth exposure apparatus that, exposes an object with an energy beamand forms a pattern on the object, the apparatus comprising: a firstmovable body which holds an object and moves within a predeterminedplane which includes a first axis and a second axis orthogonal to eachother; a second movable body which holds an object and movesindependently from the first movable body within the plane; a planarmotor which drives the first and the second movable body within theplane; and a controller which controls the planar motor, and also movesthe first movable body along a first return path located on one side ofan exposure position where the exposure is performed in a directionparallel to the second axis to a first exchange position where an objecton the first movable body is exchanged when exposure of an object heldby the first movable body has been completed, as well as move the secondmovable body along a second return path located on the other side of anexposure position in a direction parallel to the second axis to a secondexchange position where an object on the second movable body isexchanged when exposure of an object held by the second movable body hasbeen completed.

In this case, the first exchange position and the second exchangeposition can either be the same or different.

According to this apparatus, the controller controls the planar motorwhich drives the first and second movable bodies within a plane, andalso moves the first movable body along the first return path located onone side of the exposure position in a direction parallel to the secondaxis to the first exchange position where the object on the firstmovable body is exchanged when exposure of the object held by the firstmovable body has been completed, as well as move the second movable bodyalong the second return path located on the other side of the exposureposition in a direction parallel to the second axis to a second exchangeposition where the object on the second movable body is exchanged whenexposure of the object held by the second movable body has beencompleted. Therefore, by attaching a cable for wiring/piping to thefirst movable body from one side of a direction parallel to the secondaxis, and attaching a cable for wiring/piping to the second movable bodyfrom the other side of a direction parallel to the second axis, thecables can be kept from being tangled, and the length of the cables asshort as possible.

According to a fifth aspect of the present invention, there is provideda fifth exposure apparatus that exposes an object with an energy beamand forms a pattern on the object, the apparatus comprising: a firstmovable body which holds an object and moves within a predeterminedplane which includes a first axis and a second axis orthogonal to eachother; a second movable body which holds an object and movesindependently from the first movable body within the plane; a planarmotor which drives the first and the second movable body within theplane; an optical member which emits the energy beam; a liquid immersiondevice which supplies liquid in a space between the optical member andone of the first and second movable bodies, and forms a liquid immersionarea; and a controller which controls the planar motor so as to performa switching between a proximity state in which the first movable bodyand the second movable body are made to be in proximity in a directionparallel to the first axis by a predetermined distance or less and aseparation state in which both movable bodies are separated so as topass the liquid immersion area from the one movable body to the othermovable body, after exposure has been completed on an object held by theone movable body, and to move the one movable body separated from theother movable body along a return path positioned on one side of theexposure position in a direction parallel to the second axis to anexchange position where an object on the first and second movable bodiesare exchanged.

The proximity state made to be in proximity by a predetermined distanceor less, in this case, includes a state where the first movable body andthe second movable body are in contact in a direction parallel to thefirst axis, or more particularly, a state where the separation distancebetween the first movable body and the second movable body is zero. Inthis description, the term proximity state is used as a conceptincluding the state above where the separation distance is zero, or morespecifically, including a contact state, even when the state is notdefined clearly, as well as when the contact state is clearly specified.

According to this apparatus, the controller controls the planar motor soas to performs a switching between a proximity state in which the firstmovable body and the second movable body are made to be in proximity ina direction parallel to the first axis by a predetermined distance orless and a separation state in which both movable bodies are separatedso as to pass the liquid immersion area from the one movable body to theother movable body, after exposure has been completed on an object heldby the one movable body, as well as to move the one movable bodyseparated from the other movable body along a return path positioned onone side of the exposure position in a direction parallel to the secondaxis to an exchange position where an object on the first and secondmovable bodies are exchanged. Therefore, the movement range of bothmovable bodies in a direction parallel to the second axis can be setnarrower than in the case where one of the movable bodies is moved tothe exchange position along a return path positioned on one side of theexposure position in a direction parallel to the second axis and theother movable body is moved to the exchange position along a return pathpositioned on the other side of the exposure position in a directionparallel to the second axis.

According to a sixth aspect of the present invention, there is provideda movable body drive system, which drives a movable body substantiallyalong a predetermined plane, the system comprising: an encoder systemwhich has a head irradiating a detection beam on a scale having atwo-dimensional grating whose periodic directions are a first and seconddirection orthogonal to each other within a plane parallel to thepredetermined plane and receiving light from the scale, and measurespositional information of the movable body at least in directions of twodegrees of freedom within the predetermined plane including the firstand second directions based on measurement values of the head; and adrive device which drives the movable body along the predetermined planebased on measurement information of the encoder system.

According to this system, the movable body is driven along thepredetermined plane by the drive device, based on the measurementinformation of the encoder system which has a head irradiating adetection beam on a scale having a two-dimensional grating and receivingthe reflected light from the scale, and measures the positionalinformation of the movable body at least in directions of two degrees offreedom within the predetermined plane including the first and seconddirections based on measurement values of the head. Therefore, thedegree of freedom of the placement of the heads remarkably improves andlayout becomes easy when compared with the case where an encoder systemincluding a plurality of one-dimensional heads that each measures thepositional information of the movable body in the first and seconddirections is used. For example, it becomes possible to measure theposition of the movable body in directions of two degrees of freedomwithin a surface parallel to the predetermined plane by using only onescale.

According to a seventh aspect of the present invention, there isprovided a pattern formation apparatus, comprising: a movable body onwhich an object is mounted that can move substantially along a movementplane holding the object; a patterning device which generates a patternon the object; and a movable body drive system of the present inventionwhich drives the movable body for pattern formation to the object.

According to this apparatus, by generating a pattern with a patterningunit on the object on the movable body driven with good precision by themovable body drive system of the present invention, it becomes possibleto form a pattern on the object with good precision.

According to an eighth aspect of the present invention, there isprovided a sixth exposure apparatus that forms a pattern on an object byan irradiation of an energy beam, the apparatus comprising: a patterningdevice that irradiates the energy beam on the object; and the movablebody drive system of the present invention, whereby the movable bodydrive system drives the movable body on which the object is mounted forrelative movement of the energy beam and the object.

According to this apparatus, for relative movement of the energy beamirradiated on the object from the patterning device and the object, themovable body on which the object is mounted is driven with goodprecision by the movable body drive system of the present invention.Accordingly, it becomes possible to form a pattern on the object withgood precision by scanning exposure.

According to a ninth aspect of the present invention, there is provideda seventh exposure apparatus that exposes an object with an energy beam,the apparatus comprising: a movable body which can hold the object andis also substantially movable along a predetermined plane; a measurementdevice which has a measurement position where a measurement beam isirradiated placed away from an exposure position where the energy beamis irradiated in a first direction within the predetermined plane, andmeasures positional information of the object; an encoder system inwhich a scale having a two-dimensional grating and whose longitudinaldirection is in the first direction is placed on both sides of themovable body in a second direction orthogonal to the first directionwithin the predetermined plane, and a pair of head units having aplurality of heads whose positions in the second direction are differentand at least one head faceable to each of the two scales is placedfaceable to the movable body, and based on an output of two headssimultaneously facing the pair of scales, measures positionalinformation of the movable body in directions of three degrees offreedom within the predetermined plane; and a drive device which drivesthe movable body based on positional information of the movable bodymeasured by the measurement device and positional information of themovable body measured by the encoder system.

According to this apparatus, the measurement device measures thepositional information of the object on the movable body at themeasurement position where the measurement beams are irradiated that isplaced away from the exposure position within a predetermined plane inthe first direction, the encoder system measures the positionalinformation of the movable body in directions of three degrees offreedom within the predetermined plane based on the output of the twoheads that simultaneously face the two (a pair of) scales, and the drivedevice drives the movable body with good precision, based on thepositional information of the object measured by the measurement deviceand the positional information of the movable body measured by theencoder system. Therefore, it becomes possible to expose the object heldby the movable body with high accuracy. Further, the layout of the headsand the like becomes easy when compared with the case where an encodersystem including a plurality of one-dimensional heads that each measuresthe positional information of the movable body in the first and seconddirections is used.

According to a tenth aspect of the present invention, there is providedan eighth exposure apparatus that exposes an object with an energy beam,the apparatus comprising: a movable body which can hold the object andis also substantially movable along a predetermined plane; a measurementdevice which has a measurement position where a measurement beam isirradiated placed away from an exposure position where the energy beamis irradiated in a first direction within the predetermined plane, andmeasures positional information of the object; an encoder system inwhich a pair of scales having a two-dimensional grating and whoselongitudinal direction is in a second direction orthogonal to the firstdirection within the predetermined plane is placed faceable to themovable body, and a plurality of heads whose positions in the firstdirection are different and at least one head is faceable to each of thetwo scales are placed on both sides of the movable body, and based on anoutput of two heads simultaneously facing the pair of scales, measurespositional information of the movable body in directions of threedegrees of freedom within the predetermined plane; and a drive devicewhich drives the movable body based on positional information of themovable body measured by the measurement device and positionalinformation of the movable body measured by the encoder system.

According to this apparatus, the measurement device measures thepositional information of the object on the movable body at themeasurement position where the measurement beams are irradiated that isplaced away from the exposure position within a predetermined plane inthe first direction, the encoder system measures the positionalinformation of the movable body in directions of three degrees offreedom within the predetermined plane based on the output of the twoheads that simultaneously face a pair of scales, and the drive devicedrives the movable body with good precision, based on the positionalinformation of the object measured by the measurement device and thepositional information of the movable body measured by the encodersystem. Therefore, it becomes possible to expose the object held by themovable body with high accuracy. Further, the placement of the headsbecomes easy when compared with the case where an encoder systemincluding a plurality of one-dimensional heads that each measures thepositional information of the movable body in the first and seconddirections is used.

According to an eleventh aspect of the present invention, there isprovided a first device manufacturing method, including exposing anobject using one of the first and eighth exposure apparatus of thepresent invention; and developing the exposed object.

According to a twelfth aspect of the present invention, there isprovided a first exposure method in which an object is exposed with anexposure beam, the method comprising: a process in which the object ismounted on a movable body which moves along a predetermined planeincluding a first axis and a second axis orthogonal to each other; and aprocess in which at least a part of a periphery shot area of the objectis exposed, using a periphery edge exposure system placed away in adirection parallel to the first axis from a measurement system, which isplaced away in a direction parallel to the first axis direction withinthe predetermined plane from an exposure position where the exposure isperformed as well as perform a predetermined measurement on the object,while a movable body on which the object is mounted is moved along adirection parallel to the first axis.

According to this method, at least some shot areas in the periphery ofthe object are exposed by the periphery edge exposure system while themovable body on which the object is mounted is moved along a directionparallel to the first axis within the predetermined plane. This allowsthe periphery edge exposure to be performed in parallel with themovement of the object (movable body) which is moved from themeasurement system toward the exposure position, or with the movement ofthe object (movable body) in an opposite direction (for example,movement of the movable body from the exposure position to the exchangeposition of the object), which hardly reduces the throughput comparedwith when the periphery edge exposure is performed independently.

According to a thirteenth aspect of the present invention, there isprovided a second exposure method in which an object is exposed with anexposure beam, the method comprising: a process in which a movable bodythat is movable within a predetermined plane including a first axis anda second axis orthogonal to each other is made to hold an object; and aprocess in which at least a part of an exposure operation of theperiphery area is performed in parallel with a movement operation of themovable body from one of the exposure position and the exchange positionto the other, using a periphery edge exposure system which is arrangedbetween an exposure position where the exposure is performed and anexchange position of the object placed away from the exposure positionin a direction parallel to the first axis, and exposes at least a partof a periphery area which is different from an area on the object wherethe exposure is performed.

According to this method, at least a part of the exposure operation ofthe periphery areas by the periphery edge exposure system is performed,in parallel with a movement operation of the movable body from one ofthe exposure position and the exchange position to the other. Therefore,unlike the case when the periphery edge exposure is performedindependently, the throughput is hardly reduced.

According to a fourteenth aspect of the present invention, there isprovided a third exposure method in which an object is exposed with anenergy beam and a pattern is formed on the object, the methodcomprising: a process in which exposure is performed on an object heldby one of a first and second movable bodies which respectively hold anobject and independently move within a predetermined plane including afirst axis and a second axis orthogonal to each other, and in parallel,a plurality of marks on an object held by the other movable body of thefirst and second movable bodies are detected with a mark detectionsystem which has a plurality of detection areas whose position isdifferent in a direction parallel to the second axis and positional,information of the marks measured, while the other object is driven in adirection parallel to the first axis.

According to this method, a plurality of different marks of an objectheld by the other one of the first and second movable bodies is detectedwith the mark detection system having a plurality of detection areaswhose positions are different in a direction parallel to the second axisand the positional information measured while moving the other one ofthe movable bodies in a direction parallel to the first axis, inparallel with an exposure performed of an object held by one of thefirst and second movable bodies. Therefore, it becomes possible todetect the positional information of a plurality of, such as forexample, all of the marks on the object held by the other movable bodywhile the other movable body is being moved in the first axis directionfrom the position (for example, in the vicinity of the position whereexchange of the object held by the movable body is performed) in thevicinity of the plurality of detection areas of the mark detectionsystem to the exposure position, in parallel with exposure of the objectsubject to exposure held by one of the movable bodies. As a consequence,it becomes possible to achieve improvement of the throughput as well asimprovement of the overlay accuracy.

According to a fifteenth aspect of the present invention, there isprovided a fourth exposure method in which an object is exposed with anenergy beam and a pattern is formed on the object, the methodcomprising: a process in which by controlling a planar motor whichdrives the first and second movable bodies respectively holding anobject independently within a predetermined plane including a first axisand a second axis orthogonal to each other, the first movable body ismoved along a first return path located on one side of an exposureposition where the exposure is performed in a direction parallel to thesecond axis to a first exchange position where an object on the firstmovable body is exchanged when exposure of an object held by the firstmovable body has been completed, and the second movable body is alsomoved along a second return path located on the other side of theexposure position in a direction parallel to the second axis to a secondexchange position where an object on the second movable body isexchanged when exposure of an object held by the second movable body hasbeen completed.

According to this method, by controlling the planar motor which drivesthe first and second movable bodies within a plane, the first movablebody is moved along the first return path located on one side of theexposure position in a direction parallel to the second axis to thefirst exchange position where the object on the first movable body isexchanged when exposure of the object held by the first movable body hasbeen completed, and the second movable body is also moved along thesecond return path located on the other side of the exposure position ina direction parallel to the second axis to a second exchange positionwhere the object on the second movable body is exchanged when exposureof the object held by the second movable body has been completed.Therefore, by attaching a cable for wiring/piping to the first movablebody from one side of a direction parallel to the second axis, andattaching a cable for wiring/piping to the second movable body from theother side of a direction parallel to the second axis, the cables can bekept from being tangled, and the length of the cables as short aspossible.

According to a sixteenth aspect of the present invention, there isprovided a fifth exposure method in which an object is exposed with anenergy beam, the method comprising: holding the object with a movablebody; and driving the movable body with the movable body drive system ofthe present invention, and exposing the object with the energy beam.

According to this method, because the movable body holding the object isdriven with good accuracy by the movable body drive system of thepresent invention, and the object is exposed by the energy beam,exposure with high precision of the object becomes possible.

According to a seventeenth aspect of the present invention, there isprovided a sixth exposure method in which an object is exposed with anenergy beam, the method comprising: holding an object with a movablebody which is substantially movable along a predetermined plane;measuring positional information of the object on the movable body witha measurement device at a measurement position where a measurement beamis irradiated that is placed away from an exposure position where theenergy beam is irradiated in a first direction within the predeterminedplane; measuring positional information of the movable body indirections of three degrees of freedom within the predetermined planewith an encoder system in which a pair of scales having atwo-dimensional grating and whose longitudinal direction is in the firstdirection is placed on the movable body separately in a second directionorthogonal to the first direction within the predetermined plane, and apair of head units having a plurality of heads whose positions in thesecond direction are different and at least one head faceable to each ofthe pair of scales is placed faceable to the movable body; and drivingthe movable body based on positional information which has been measuredand the measurement information of the encoder system and exposing theobject with the energy beam.

According to this method, the positional information of the object onthe movable body is measured at the measurement position where themeasurement beam is irradiated placed apart from the exposure positionin the first direction within the predetermined plane, and by theencoder system, the positional information of the movable body indirections of three degrees of freedom within the predetermined plane ismeasured. And by driving the movable body based on the positionalinformation which has been measured and the measurement information ofthe encoder system, the object is exposed by the energy beam.Accordingly, the object can be exposed with high precision.

According to an eighteenth aspect of the present invention, there isprovided a seventh exposure method in which an object is exposed with anenergy beam, the method comprising: holding an object with a movablebody which is substantially movable along a predetermined plane;measuring positional information of the object on the movable body witha measurement device at a measurement position where a measurement beamis irradiated that is placed away from an exposure position where theenergy beam is irradiated in a first direction within the predeterminedplane; measuring positional information of the movable body indirections of three degrees of freedom within the predetermined plane,with an encoder system in which a pair of scales having atwo-dimensional grating and whose longitudinal direction is in a seconddirection orthogonal to the first direction within the predeterminedplane is placed faceable to the movable body, and a plurality of headswhose positions in the first direction are different and at least onehead is faceable to the pair of scales are placed on both sides of themovable body; and driving the movable body based on positionalinformation which has been measured and the measurement information ofthe encoder system and exposing the object with the energy beam.

According to this method, the positional information of the object onthe movable body is measured at the measurement position where themeasurement beam is irradiated placed apart from the exposure positionin the first direction within the predetermined plane, and by theencoder system, the positional information of the movable body indirections of three degrees of freedom within the predetermined plane ismeasured. And by driving the movable body based on the positionalinformation which has been measured and the measurement information ofthe encoder system, the object is exposed by the energy beam.Accordingly, the object can be exposed with high precision.

According to a nineteenth aspect of the present invention, there isprovided a second device manufacturing method, the method including:exposing an object and forming a pattern by one of the first and seventhexposure method of the present invention; and developing an object onwhich the pattern has been formed.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings;

FIG. 1 is a view that schematically shows a configuration of an exposureapparatus related to a first embodiment;

FIG. 2 is a planar view that shows a wafer stage;

FIG. 3 is a planar view that shows a measurement stage;

FIG. 4 is a view used to explain an interferometer system;

FIG. 5 is a planar view that shows a stage device and variousmeasurement devices;

FIG. 6 is a view used to explain a placement of heads of an encodersystem, an alignment system, a periphery edge exposure unit and thelike;

FIG. 7 is a view used to explain a placement of a multipoint AF systemand Z heads of a surface position measurement system;

FIG. 8 is a view used to explain an active mask used in a periphery edgeexposure;

FIGS. 9A and 9B are views used to explain an on state and an off stateof a micromirror, respectively;

FIG. 10 is a block diagram that shows a main configuration of a controlsystem of the exposure apparatus in FIG. 1;

FIG. 11 is a view used to explain a shot map of a wafer;

FIG. 12 is a view used to explain an alignment shot area of a wafer;

FIG. 13 is a view used to explain an area subject to periphery edgeexposure;

FIG. 14 is a view that shows a state of the wafer stage and themeasurement stage where exposure to a wafer on the wafer stage isperformed by a step-and-scan method;

FIG. 15 is a view that shows a state of both stages at the time ofunloading of a wafer (when the measurement stage reaches the positionwhere Sec-BCHK (interval) is performed);

FIG. 16 is a view that shows a state of both stages at the time ofloading of a wafer;

FIG. 17 is a view that shows a state of both stages at the time ofswitching (when the wafer stage has moved to a position where the formerprocessing of Pri-BCHK is performed) from stage servo control by aninterferometer to stage servo control by an encoder;

FIG. 18 is a view that shows a state of the wafer stage and themeasurement, stage when alignment marks arranged in three firstalignment shot areas are being simultaneously detected using alignmentsystems AL1, AL2 ₂ and AL2 ₃;

FIG. 19 is a view that shows a state of the wafer stage and themeasurement stage when the former processing of focus calibration isbeing performed;

FIG. 20 is a view that shows a state of the wafer stage and themeasurement stage when alignment marks arranged in five second alignmentshot areas are being simultaneously detected using alignment systems AL1and AL2 ₁ to AL2 ₄;

FIG. 21 is a view that shows a state of the wafer stare and themeasurement stage when at least one of the latter processing of Pri-BCHKand the latter processing of focus calibration is being performed;

FIG. 22 is a view that shows a state of the wafer stage and themeasurement stage when alignment marks arranged in five third alignmentshot areas are being simultaneously detected using alignment systems AL1and AL2 ₁ to AL2 ₄;

FIG. 23 is a view that shows a state of the wafer stage and themeasurement stage when alignment marks arranged in three fourthalignment shot areas are being simultaneously detected using alignmentsystems AL1, AL2 ₂ and AL2 ₃;

FIG. 24 is a view that shows a state of the wafer stage and themeasurement stage when the focus mapping has ended;

FIGS. 25A to 25F are views used to explain a proceeding process of aperiphery edge exposure, respectively;

FIG. 26 is a view that shows all the areas exposed by periphery edgeexposure;

FIG. 27 is a view that schematically shows a configuration of anexposure apparatus related to a second embodiment;

FIG. 28 is a planar view that shows a wafer stage;

FIG. 29 is a planar view that shows a placement of a stage device and aninterferometer which exposure apparatus of FIG. 27 is equipped with;

FIG. 30 is a planar view that shows a placement of a stage device and asensor unit which exposure apparatus of FIG. 27 is equipped with;

FIG. 31 is a planar view that shows a placement of an encoder head andan alignment system;

FIG. 32 is a block diagram that shows a main configuration of a controlsystem of an exposure apparatus related to a second embodiment;

FIG. 33 is a view used to explain a position measurement within an XYplane of the wafer table by a plurality of encoders respectivelyincluding a plurality of heads and a switching linkage) of heads;

FIG. 34 is a view that shows an example of a configuration of anencoder;

FIG. 35 is a view that shows a state of the wafer stage and themeasurement stage when exposure to a wafer is performed by astep-and-scan method;

FIG. 36 is a view that shows a state of the wafer stage and themeasurement stage at the time of unloading of a wafer;

FIG. 37 is a view that shows a state of the wafer stage and themeasurement stage at the time of loading of a wafer;

FIG. 38 is a view that shows a state of the wafer stage and themeasurement stage, and the placement of encoder heads at the time ofswitching from stage servo control by an interferometer to stage servocontrol by an encoder;

FIG. 39 is a view used to explain a state of the wafer stage and themeasurement stage at the time of wafer alignment;

FIG. 40 is a planar view that shows a stage device which an exposureapparatus of a third embodiment is equipped with and a placement of asensor unit;

FIG. 41 is a block diagram that shows a main configuration of a controlsystem of an exposure apparatus related to a third embodiment;

FIG. 42 is a view that schematically shows a configuration of anexposure apparatus of a fourth embodiment;

FIG. 43 is a side view that shows a wafer stage WST1 of FIG. 42, andFIG. 43B is a planar view that shows wafer stage WST1;

FIG. 44A is a side view that shows a wafer stage WST2 of FIG. 42, andFIG. 44B is a planar view that shows wafer stage WST2;

FIG. 45 is a view used to explain a placement of heads and the like ofan encoder system, a surface position measurement system and the likethat constitute a measurement system which the wafer stage device ofFIG. 42 is equipped with;

FIG. 46 is a view used to explain a configuration of an interferometersystem which constitutes the measurement system;

FIG. 47 is a block diagram that shows a main configuration of a controlsystem of an exposure apparatus of a second embodiment;

FIG. 48 is a view (No. 1) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 49 is a view (No. 2) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 50 is a view (No. 3) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 51 is a view (No. 4) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 52 is a view (No. 5) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 53 is a view (No. 6) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 54 is a view (No. 7) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 55 is a view (No. 8) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 56 is a view (No. 9) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 57 is a view (No. 10) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 58 is a view (No. 11) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 59 is a view (No. 12) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 60 is a view (No. 13) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 61 is a view (No. 14) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 62 is a view (No. 15) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 63 is a view (No. 16) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 64 is a view (No. 17) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 65 is a view (No. 18) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 66 is a view (No. 19) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 67 is a view (No. 20) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 68 is a view (No. 21) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 69 is a view (No. 22) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 70 is a view (No. 23) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 71 is a view (No. 24) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 72 is a view (No. 25) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 73 is a view (No. 26) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 74 is a view (No. 27) used to explain a parallel processingoperation using wafer stage WST1 and WST2;

FIG. 75 is a view (No. 28) used to explain a parallel processingoperation using wafer stage WST1 and WST2; and

FIG. 76 is a view (No. 29) used to explain a parallel processingoperation using wafer stage WST1 and WST2.

DESCRIPTION OF THE EMBODIMENTS

A First Embodiment

Hereinafter, a first embodiment of the present invention will bedescribed, with reference to FIGS. 1 to 26.

FIG. 1 schematically shows a configuration of an exposure apparatus 100in the first embodiment. Exposure apparatus 100 is a projection exposureapparatus by the step-and-scan method, or a so-called scanner. As itwill be described later, a projection optical system PL is arranged inthe embodiment, and in the description below, a direction parallel to anoptical axis AX of projection optical system PL will be described as theZ-axis direction, a direction within a plane orthogonal to the Z-axisdirection in which a reticle and a wafer are relatively scanned will bedescribed as the Y-axis direction, a direction orthogonal to the Z-axisand the Y-axis will be described as the X-axis direction, and rotational(inclination) directions around the X-axis, the Y-axis, and the Z-axiswill be described as θx, θy, and θz directions, respectively.

Exposure apparatus 100 is equipped with an illumination system 10, areticle stage RST, a projection unit PU, a stage device 50 having awafer stage WST and a measurement stage MST, and a control system ofthese parts. In FIG. 1, a wafer W is mounted on wafer stage WST.

Illumination system 10 includes a light source, an illuminanceuniformity optical system that has an optical integrator and the like,and an illumination optical system that has a reticle blind (none ofwhich are shown), as is disclosed in, for example, U.S. PatentApplication Publication No. 2003/0025890 and the like. Illuminationsystem 10 illuminates a slit-shaped illumination area IAR, which is seton reticle R with a reticle blind (a masking system) by an illuminationlight (exposure light) IL with a substantially uniform illuminance. Inthis case, as illumination light IL, for example, an ArF excimer laserbeam (wavelength 193 nm) is used.

On reticle stage RST, reticle R on which a circuit pattern or the likeis formed on its pattern surface (the lower surface in FIG. 1) is fixed,for example, by vacuum chucking. Reticle stage RST is finely drivablewithin an XY plane, for example, by a reticle stage drive system 11 (notshown in FIG. 1, refer to FIG. 10) that includes a linear motor or thelike, and reticle stage RST is also drivable in a scanning direction (inthis case, the Y-axis direction, which is the lateral direction of thepage surface in FIG. 1) at a predetermined scanning speed.

The positional information (including information on position(hereinafter also appropriately described as θz rotation (or θz rotationquantity), or yawing (or yawing amount)) in the θz direction) of reticlestage RST in the XY plane is constantly detected at a resolution of, forexample, around 0.25 nm by a reticle laser interferometer (hereinafterreferred to as a “reticle interferometer”) 116, via a movable mirror 15(the mirrors actually arranged are a Y movable mirror (or a retroreflector) that has a reflection surface which is orthogonal to theY-axis direction and an X movable mirror that has a reflection surfaceorthogonal to the X-axis direction). The measurement values of reticleinterferometer 116 are sent to a main controller 20 (not shown in FIG.1, refer to FIG. 10).

Projection unit PU is placed below reticle stage RST in FIG. 1.Projection unit PU includes a barrel 40, and projection optical systemPL stored within barrel 40. As projection optical system PL, forexample, a dioptric system is used, consisting of a plurality of lenses(lens elements) that is disposed along optical axis AX, which isparallel to the Z-axis direction. Projection optical system PL is, forexample, a both-side telecentric dioptric system that has apredetermined projection magnification (such as one-quarter times,one-fifth times, or one-eighth times). Therefore, when illuminationsystem 10 illuminates illumination area IAR on reticle R, byillumination light IL which has passed through reticle R placed so thatits pattern surface substantially coincides with a first surface (objectsurface) of projection optical system PL, a reduced image of the circuitpattern of reticle R within illumination area IAR via projection opticalsystem PL (projection unit PU) is formed on an area (hereinafter alsoreferred to as an exposure area) IA conjugate with illumination area IARon a wafer W whose surface is coated with a resist (sensitive agent) andis placed on a second surface (image plane surface) side of projectionoptical system PL. And by reticle stage RST and wafer stage WST beingsynchronously driven, reticle R is relatively moved in the scanningdirection (the Y-axis direction) with respect to illumination area IAR(illumination light IL) while wafer W is relatively moved in thescanning direction (the Y-axis direction) with respect to exposure areaIA (illumination light IL), thus scanning exposure of a shot area(divided area) on wafer W is performed, and the pattern of reticle R istransferred onto the shot area. That is, in the embodiment, the patternis generated on wafer W according to illumination system 10, reticle R,and projection optical system PL, and then by the exposure of thesensitive layer (resist layer) on wafer W with illumination light IL,the pattern is formed on wafer W.

In exposure apparatus 100 of the embodiment, a local liquid immersiondevice 8 is installed to perform exposure by a liquid immersion method.Local liquid immersion device 8, for example, includes a liquid supplydevice 5, a liquid recovery device 6 (both of which are not shown inFIG. 1, refer to FIG. 10), a liquid supply pipe 31A, a liquid recoverypipe 31B, a nozzle unit 32 and the like. As shown in FIG. 1, nozzle unit32 is supported in a suspended state by a mainframe (not shown) holdingprojection unit PU, so that the periphery of the lower end portion ofbarrel 40 that holds an optical element closest to the image plane side(the wafer W side) constituting projection optical system PL, in thiscase, a lens (hereinafter also referred to as a “tip lens”) 191, isenclosed. In the embodiment, as shown in FIG. 1, the lower end surfaceof nozzle unit 32 is set to be on a substantially flush surface with thelower end surface of tip lens 191. Further, nozzle unit 32 is equippedwith a supply opening and a recovery opening of a liquid Lq, a lowersurface to which wafer W is placed facing and at which the recoveryopening is arranged, and a supply flow channel and a recovery flowchannel that are connected to a liquid supply pipe 31A and a liquidrecovery pipe 31B respectively. Liquid supply pipe 31A and liquidrecovery pipe 31B are slanted by around 45 degrees relative to an X-axisdirection and Y-axis direction in a planar view (when viewed from above)as shown in FIG. 5, and are placed symmetric to a straight line (areference axis) LV₀ which passes through the center (optical axis AX ofprojection optical system PL, coinciding with the center of exposurearea IA previously described in the embodiment) of projection unit PUand is also parallel to the Y-axis.

Liquid supply pipe 31A connects to liquid supply device 5 (not shown inFIG. 1, refer to FIG. 10), and liquid recovery pipe 31B connects toliquid recovery device 6 (not shown in FIG. 1, refer to FIG. 10). Inthis case, in liquid supply device 5, a tank to store the liquid, acompression pump, a temperature controller, a valve for controlling theflow amount of the liquid, and the like are equipped. In liquid recoverydevice 6, a tank to store the liquid which has been recovered, a suctionpump, a valve for controlling the flow amount of the liquid, and thelike are equipped.

Main controller 20 controls liquid supply device 5 (refer to FIG. 10),and supplies liquid Lq between tip lens 191 and wafer W via liquidsupply pipe 31A, as well as control liquid recovery device 6 andrecovers liquid Lq from between tip lens 191 and wafer W via liquidrecovery pipe 31B. During the operations, main controller 20 controlsliquid supply device 5 and liquid recovery device 6 so that the quantityof liquid Lq supplied constantly equals the quantity of liquid Lq whichhas been recovered. Accordingly, in the space between tip lens 191 andwafer W, a constant quantity of liquid Lq (refer to FIG. 1) is heldconstantly replaced, and by this, a liquid immersion area 14 (refer toFIG. 14) is formed. Incidentally, in the case measurement stage MSTwhich will be described later on is positioned below projection unitliquid immersion area 14 can be formed similarly in the space betweentip lens 191 and the measurement table.

In the embodiment, as the liquid described above, pure water(hereinafter, it will simply be referred to as “water” besides the casewhen specifying is necessary) that transmits the ArF excimer laser light(light with a wavelength of 193 nm) is to be used. Incidentally,refractive index n of the water with respect to the ArF excimer laserbeam is around 1.44, and in the water the wavelength of illuminationlight IL is 193 nm×1/n, shortened to around 134 nm.

As shown in FIG. 1, stage device 50 is equipped with a wafer stage WSTand a measurement stage MST placed above a base board 12, a measurementsystem 200 (refer to FIG. 10) which measures positional information ofthe stages WST and MST, a stage drive system 124 (refer to FIG. 10)which drives stages WST and MST and the like. Measurement system 200includes an interferometer system 118, an encoder system 150, and asurface position measurement system 180 as shown in FIG. 10.

Wafer stage WST and measurement stage MST are supported on base board12, via a clearance of around several μm by noncontact bearings (notshown) fixed to each of the bottom surfaces, such as, for example, airbearings. Further, stages WST and MST are independently drivable withinthe XY plane by stage drive system 124 (refer to FIG. 10), whichincludes, for example, a linear motor and the like.

Wafer stage WST includes a stage main section 91, and a wafer table WTBthat is mounted on stage main section 91. Wafer table WTB and stage mainsection 91 are configured, for example, drivable in directions of sixdegrees of freedom (X, Y, Z, θx, θy, and θz) with respect to base board12 by a drive system including a linear motor and a Z leveling mechanism(including a voice coil motor and the like) (none of which are shown).

In the center of the upper surface of wafer table WTB, a wafer holder(not shown) is arranged which holds wafer W by vacuum suction or thelike. On the outer side of the wafer holder (mounting area of thewafer), as shown in FIG. 2, a plate (a liquid repellent plate) 28 isarranged that has a circular opening one size larger than the waferholder formed in the center, and also has a rectangular outer shape(contour). A liquid repellent treatment against liquid. Lq is applied tothe surface of plate 28. Incidentally, plate 28 is installed so that itsentire surface (or a part of its surface) becomes flush with the surfaceof wafer W.

Plate 28 has a first liquid repellent area 28 a having a rectangularouter shape (contour) with the opening formed in the center, and asecond liquid repellent area 28 b having a rectangular frame (loop)shape placed around the first liquid repellent area 28 a. Incidentally,in the embodiment, water is used as liquid Lq as is described above, andtherefore, hereinafter the first liquid repellent area 28 a and thesecond liquid repellent area 28 b are also referred to as a first waterrepellent plate 28 a and a second water repellent plate 28 b.

On an end on the +Y side of the first water repellent plate 28 a, ameasurement plate 30 is arranged. On measurement plate 30, a fiducialmark FM is arranged in the center, and a pair of aerial imagemeasurement slit patterns (slit-shaped measurement patterns) SL isarranged with fiducial mark FM in between. And, in correspondence witheach aerial image measurement slit pattern SL, a light-transmittingsystem (not shown) which guides illumination light IL having passedthrough the slit patterns outside wafer stage WST (a photodetectionsystem arranged in measurement stage MST which will be described lateron) is arranged.

On the second liquid repellent area 28 b, on the upper surface in areason one side and the other side in the X-axis direction (the horizontaldirection of the page surface in FIG. 2) Y scales 39Y₁ and 39Y₂ areformed, respectively. Y scales 39Y₁ and 39Y₂ are each composed of a:reflective grating (for example, a diffraction grating) having aperiodic direction in the Y-axis direction in which grid lines 33 havingthe longitudinal direction in the X-axis direction are placed in apredetermined pitch along a direction parallel to the Y-axis (the Y-axisdirection).

Similarly, on the upper surface of the second liquid repellent area 28 bin areas on one side and the other side in the Y-axis direction (thevertical direction of the page surface in FIG. 2), X scales 39X₁ and39X₂ are formed, respectively. X scales 39X₁ and 39X₂ are each composedof a reflective grating (for example, a diffraction grating) having aperiodic direction in the X-axis direction in which grid lines 37 havingthe longitudinal direction in the Y-axis direction are placed in apredetermined pitch along a direction parallel to the X-axis (the X-axisdirection). Each scale is created by marking the graduations of thediffraction grating, for example, in a pitch between 138 nm to 4 μm, forexample, a pitch of 1 μm on a thin plate shaped glass. These scales arecovered with the liquid repellent film (water repellent film) describedabove. Incidentally, the pitch of the grating is shown much wider inFIG. 2 than the actual pitch, for the sake of convenience. The same istrue also in other drawings. Incidentally, in order to protect thediffraction grating, the diffraction grating can be covered with a glassplate with low thermal expansion that has water repellency so that thesurface of the glass plate becomes the same height (surface position) asthe surface of the wafer. In this case, as the glass plate, a platewhose thickness is the same level as the wafer, such as for example, aplate 1 mm thick, can be used.

Incidentally, a pattern for positioning (not shown) is arranged fordeciding the relative position between an encoder head and a scale nearthe edge of each scale (to be described later). The pattern forpositioning is configured, for example, from grid lines that havedifferent reflectivity, and when the encoder head scans the pattern, theintensity of the output signal of the encoder changes. Therefore, athreshold value is determined beforehand, and the position where theintensity of the output signal exceeds the threshold value is detected.Then, the relative position between the encoder head and the scale isset, with the detected position as a reference.

On the −Y edge surface and the −X edge surface of wafer table WTB, asshown in FIGS. 2, 4 and the like, a reflection surface 17 a and areflection surface 17 b used in the interferometer system (to bedescribed later) are formed.

Measurement stage MST has a stage main section 92 driven in the XY planeby a linear motor and the like (not shown), and a measurement table MTBmounted on stage main section 92, as shown in FIG. 1. Measurement stageMST is configured drivable in at least directions of three degrees offreedom (X, Y, and θz) with respect to base board 12 by a drive system(not shown).

Incidentally, in FIG. 10, the drive system of wafer stage WST and thedrive system of measurement stage MST are included and are shown asstage drive system 124.

Various measurement members are arranged at measurement table MTB (andstage main section 92). As such measurement members, for example, asshown in FIG. 3, members such as an uneven illuminance measuring sensor94, an aerial image measuring instrument 96, a wavefront aberrationmeasuring instrument 98, an illuminance monitor (not shown) and the likeare arranged. Further, in stage main section 92, a pair ofphotodetection systems (not shown) is arranged in a placement facing thepair of light-transmitting systems (not shown) previously described. Inthe embodiment, an aerial image measuring unit 45 (refer to FIG. 10) isconfigured in a state where wafer stage WST and measurement stage MSTare in proximity within a predetermined distance in the Y-axis direction(including a contact state) and illumination lights IL that has beentransmitted through each aerial image measurement slit pattern SL ofmeasurement plate 30 on wafer stage WST are guided by eachlight-transmitting system (not shown) and are received bylight-receiving elements of each photodetection system (not shown)within measurement stage MST.

On the −Y side end surface of measurement table MTB, a fiducial bar(hereinafter, shortly referred to as an “FD bar”) 46 is arrangedextending in the X-axis direction, as shown in FIG. 3. FD bar 46 iskinematically supported on measurement stage MST by a full-kinematicmount structure. Since FD bar 46 serves as a prototype standard(measurement standard), optical glass ceramics with a low coefficient ofthermal expansion, such as Zerodur (the brand name) of Schott AG areemployed as the materials. In the vicinity of the end portions on oneside and the other side in the longitudinal direction of FD bar 46, areference grating (for example, a diffraction grating) 52 whose periodicdirection is the Y-axis direction is respectively formed, placedsymmetric to a center line CL. Further, on the upper surface of FD bar46, a plurality of reference marks M is formed. As each of referencemarks M, a two-dimensional mark having a size that can be detected by aprimary alignment system and secondary alignment systems (to bedescribed later) is used. Incidentally, the surface of FD bar 46 and thesurface of measurement table MTB are al so covered with a liquidrepellent film (water repellent film).

On the end surface on the +Y side and the −X side end surface ofmeasurement table MTB, reflection surfaces 19 a and 19 b are formedsimilar to wafer table WTB (refer to FIG. 3).

In exposure apparatus 100 of the embodiment, a primary alignment systemAL1 having a detection center at a position spaced apart from opticalaxis AX of projection optical system PL at a predetermined distance onthe −Y side is arranged on reference axis LV₀ previously described asshown in FIG. 6. Primary alignment system AL1 is fixed to the lowersurface of the mainframe (not shown). On one side and the other side inthe X-axis direction with primary alignment system AL1 in between,secondary alignment systems AL2 ₁ and AL2 ₂, and AL2 ₃ and AL2 ₄ whosedetection centers are substantially symmetrically placed with respect toreference axis LV ₀ are severally arranged. Secondary alignment systemsAL2 ₁ to AL2 ₄ are fixed via a movable support member (not shown) to thelower surface of the mainframe (not shown), and by using drivemechanisms 60 ₁ to 60 ₄ (refer to FIG. 10), the relative position of thedetection areas can be adjusted in the X-axis direction. Incidentally, astraight line (a reference axis) LA which passes through the detectioncenter of primary alignment system. AL1 and is parallel to the X-axisshown in FIG. 6 and the like coincides with the optical axis of ameasurement beam 136 from interferometer 127 previously described.

In the embodiment, as each alignment system AL1 and AL2 ₁ to AL2 ₄, forexample, an FIA (Field Image Alignment) system by an image processingmethod is used. The imaging signals from each of alignment systems AL1and AL2 ₁ to AL2 ₄ are supplied to main controller 20, via a signalprocessing system (not shown).

Next, a configuration and the like of: interferometer system 118 (referto FIG. 10), which measures the positional information of wafer stageWST and measurement stage MST, will be described.

Interferometer system 118 includes a Y interferometer 16, Xinterferometers 126, 127, and 128, and Z interferometers 43A and 43B forposition measurement of wafer stage WST, a Y interferometer 18 and an Xinterferometer 130 for position measurement of measurement stage MST andthe like, as shown in FIG. 4. Y interferometer 16 and the three Xinterferometers 126, 127, and 128 each irradiate interferometer beams(measurement beams) B4 (B4 ₁, B4 ₂), B5 (B5 ₁, B5 ₂), B6, and B7 onreflection surfaces 17 a and 17 b of wafer table WTB. And, Yinterferometer 16, and the three X interferometers 126, 127, and 128each receive the reflected lights, and measure the positionalinformation of wafer stage WST in the XY plane, and supply thepositional information which has been measured to main controller 20.

In this case, for example, X interferometer 126 irradiates at leastthree measurement beams parallel to the X-axis including a pair ofmeasurement beams B5 ₁ and B5 ₂ which passes through optical axis (inthe embodiment, also coinciding with the center of exposure area IApreviously described) AX of projection optical system PL and issymmetric about a straight line (reference axis LH (refer to FIG. 5 andthe like)) parallel to the X-axis. Further, Y interferometer 16irradiates at least three measurement beams parallel to the Y-axisincluding a pair of measurement beams B4 ₁, B4 ₂, which are symmetricabout reference axis LV₀ previously described, and B3 on reflectionsurface 17 a and a movable mirror 41 (to be described later on). Asdescribed, in the embodiment, as each interferometer, a multiaxialinterferometer which a plurality of measurement axis is used, with anexception for a part of the interferometers (for example, interferometer128). Therefore, based on measurement results of Y interferometer 16 andX interferometers 126 or 127, main controller 20 can also compute theposition of wafer table WTB (wafer stage WST) in the θx direction(hereinafter appropriately expressed as θx rotation (or ex rotationquantity), or pitching (or pitching amount)), the position in the θydirection (hereinafter appropriately expressed as θy rotation (or θyrotation quantity), or rolling (or rolling amount)), and the θz rotation(that is, yawing amount), in addition to the X, Y positions.

Further, as shown in FIG. 1, movable mirror 41 having a concave-shapedreflection surface is attached to the side surface on the −Y side ofstage main section 91. As it can be seen from FIG. 2, movable mirror 41is designed so that the length in the X-axis direction is longer thanreflection surface 17 a of wafer table WTB.

A pair of Z interferometers 43A and 43B are arranged (refer to FIGS. 1and 4), facing movable mirror 41. Z interferometers 43A and 43Birradiate two measurement beams B1 and B2, respectively, on fixedmirrors 47A and 47B, which are fixed, for example, on the mainframe (notshown) supporting projection unit PU, via movable mirror 41. And byreceiving each reflected light, Z interferometers 43A and 43B measurethe optical path length of measurement beams B1 and B2. And from theresults, main controller 20 computes the position of wafer stage WST infour degrees of freedom (Y, Z, θy, and θz) directions.

In the embodiment, the position within the XY plane (including therotation information in the θz direction) of wafer stage WST (wafertable WTB) is mainly measured by an encoder system (to be describedlater), interferometer system 118 is used when wafer stage WST ispositioned outside the measurement area (for example, near unloadingposition UP and loading position LP as shown in FIG. 5) of the encodersystem. Further, interferometer system 118 is used secondarily such aswhen correcting (calibrating) a long-term fluctuation (for exampletemporal deformation of the scale) of the measurement results of theencoder system, or as backup at the time of output abnormality in theencoder system. As a matter of course, the position of wafer stage WST(wafer table WTB) can be controlled using both interferometer system 118and the encoder system together.

Y interferometer 18 and X interferometer 130 of interferometer system118 irradiate interferometer beams (measurement beams) on reflectionsurfaces 19 a and 19 b of measurement table MTB as shown in FIG. 4, andmeasure the positional information of measurement stage MST (including,for example, at least the position in the X-axis and the Y-axisdirections and the rotation information in the θz, direction) byreceiving the respective reflected lights, and supply the measurementresults to main controller 20.

Next, the structure and the like of encoder system 150 (refer to FIG.10) which measures the positional information of wafer stage WST in theXY plane (including rotation information in the θz direction) will bedescribed. The main configuration of encoder system 150 is disclosed,such as in, for example, U.S. Patent Application Publication No.2008/0088843 and the like.

In exposure apparatus 100, as shown in FIG. 5, four head units 62A, 62B,62C and 62D are placed on the +X side, +Y side, and −X side of nozzleunit 32, and the −Y side of primary alignment system AL1, respectively.Further, on the −Y side of each of the head units 62C and 62A and alsoat a Y position almost the same as primary alignment system AL1, headunits 62E and 62F are arranged, respectively. Head units 62A to 62F arefixed to the mainframe (not shown) holding projection unit PU in asuspended state, via a support member.

As shown in FIG. 6, head unit 62A is placed on the +X side of nozzleunit 32, and is equipped with a plurality of (in this case, four) Yheads 65 ₂ to 65 ₅ placed on reference axis LH previously describedalong the X-axis direction at a distance WD, and a Y head 65 ₁ placed ata position on the −Y side of nozzle unit 32 a predetermined distanceaway in the −Y direction from reference axis LH. In this case, thedistance in the X-axis direction of Y heads 65 ₁ and 65 ₂ is also setapproximately equal to WD. As shown in FIG. 6, head unit 620 isconfigured symmetrical to head unit 62A, and is placed symmetrical withrespect to reference axis LV₀ previously described. Head unit 620 isequipped with five Y heads 64 ₁ to 64 ₅, which are placed symmetrical toY heads 65 ₅ to 65 ₁, with respect to reference axis LV₀. Hereinafter, Yheads 65 ₁ to 65 ₅ and 64 ₁ to 64 ₅ will also be described as Y heads 65and 64, respectively, as necessary.

Head unit 62A constitutes a multiple-lens (five-lens, in this case) Ylinear encoder (hereinafter appropriately shortened to “Y encoder” or“encoder”) 70A (refer to FIG. 10) that measures the position of waferstage WST (wafer table WTB) in the Y-axis direction (the Y-position)using Y scale 39Y, previously described. Similarly, head unit 62Cconstitutes a multiple-lens (five-lens, in this case) Y linear encoder70C (refer to FIG. 10) that measures the Y-position of wafer stage WST(wafer table WTB) using Y scale 39Y₂ described above. In this case, ofthe five Y heads 64 _(i) and 65 _(j) that head units 62A and 62C areeach equipped with, distance WD in the X-axis direction of adjacent Yheads (to be more accurate, the irradiation points of the measurementbeams generated by Y heads 65 and 64 on the scale) is set slightlynarrower than the width (to be more precise, the length of grid line 38)of Y scales 39Y₂ and 39Y₁ in the X-axis direction. Accordingly, onexposure and the like, of the respective five Y heads 65 _(j) and 64_(i) at one head each constantly faces the corresponding Y scales 39Y₁and 39Y₂.

As shown in FIG. 6, head unit 62B is placed on the +Y side of nozzleunit 32 (projection unit PU), and is equipped with a plurality of, inthis case, four X heads 66 ₅ to 66 ₈ that are placed on reference axisLV₀ previously described along Y-axis direction at distance WD. Further,head unit 62D is placed on the −Y side of primary alignment system AL1,and is equipped with a plurality of, in this case, four X heads 66 ₁ to66 ₄ that are placed on reference axis LV₀ at distance WD. Hereinafter,X heads 66 ₁ to 66 ₈ will also be described as X heads 66, as necessary.

Head unit 62B constitutes a multiple-lens (four-lens, in this case) Xlinear encoder (hereinafter, shortly referred to as an “X encoder” or an“encoder” as needed) 70B (refer to FIG. 10) that measures the positionin the X-axis direction (the X-position) of wafer stage WST (wafer tableWTB) using X scale 39X₁ described above. Further, head unit 62Dconstitutes a multiple-lens (four-lens, in this case) X linear encoder70D (refer to FIG. 10) that measures the X-position of wafer stage WST(wafer table WTB) using X scale 39X₂ previously described.

Here, of the four X heads 66 ₁ to 66 ₄ and 66 ₅ to 66 ₈ that head units62B and 62D are equipped with, respectively, distance WD betweenadjacent X heads 66 (to be more accurate, the irradiation point of themeasurement beam generated by X head 66 on the scale) in the Y-axisdirection is set shorter than the width of X scales 39X₁ and 39X₂ (to bemore accurate, the length of grid line 37) in the Y-axis direction.Accordingly, at times such as exposure or wafer alignment, at least onehead of the four X heads 66 each, or more specifically, the eight Xheads 66 that head units 62B and 62D are equipped with, constantly facesthe corresponding X scales 39X₁ and 39X₂. Incidentally, the distancebetween X head 66 ₅ farthest to the −Y side of head unit 62B and X head66 ₄ farthest to the +Y side of head unit 62D is set slightly narrowerthan the width of wafer table WTB in the Y-axis direction so thatswitching (linkage described below) becomes possible between the two Xheads by the movement of wafer stage WST in the Y-axis direction.

As shown in FIG. 6, head unit 62E is equipped with three Y heads 67 ₁ to67 ₃ placed on the −X side of the secondary alignment system AL2 ₁ onreference axis LA previously described at substantially the samedistance as distance WD, and a Y head 674 placed on the +Y side of thesecondary alignment system AL2 ₁ located a predetermined distance awayin the +Y direction from reference axis LA. In this case, the distancebetween. Y heads 67 ₃ and 67 ₄ in the X-axis direction is also set toWD. Hereinafter, Y heads 67 ₁ to 67 ₄ will also be described,appropriately, as Y head 67.

Head unit 62F is symmetrical to head unit 62E with respect to referenceaxis LV₀ previously described, and is equipped with four Y heads 68 ₁ to68 ₄ which are placed in symmetry to four Y heads 67 ₄ to 67 ₁ withrespect to reference axis LV₀. Hereinafter, Y heads 68 ₁ to 68 ₄ willalso be described, appropriately, as Y head 68.

On alignment operation and the like which will be described later on, atleast one each of Y heads 67 _(p) and 68 _(q) (p, q=1 to 4) face Yscales 39Y₂ and 39Y₁, respectively. The Y position (and θz rotation) ofwafer stage WST is measured by these Y heads 67 _(p) and 68 _(q) (morespecifically, Y encoders 70E and 70F configured by Y heads 67 _(p) and68 _(q)).

Further, in the embodiment, at the time of baseline measurement and thelike of the secondary alignment system which will be described later on,Y head 67 ₃ and 68 ₂ which are adjacent to the secondary alignmentsystems AL2 ₁ and AL2 ₄ in the X-axis direction face a pair of referencegratings 52 of FD bar 46, respectively, and by Y heads 67 ₃ and 68 ₂that face the pair of reference gratings 52, the Y position of FD bar 46is measured at the position of each reference grating 52. In thedescription below, encoders configured by Y heads 67 ₃ and 68 ₂ whichface the pair of reference gratings 52, respectively, will be referredto as Y encoders 70E₂ and 70F₂, and for identification, Y encoders 70Eand 70F configured by Y heads 67 and 68 that face Y scales 39Y₂ and 39Y₁previously described, will be referred to as Y encoders 70E₁ and 70F₁.

The measurement values of encoders 70A to 70F described above aresupplied to main controller 20, and main controller 20 controls theposition within the XY plane of wafer stage WST based on threemeasurement values of encoders 70A to 70D or on three measurement valuesof encoders 70B, 70D, 70E₁, and 70F₁, and also controls the rotation(yawing) in the θz direction of FD bar 46 (measurement stage FST) basedon the measurement values of encoders 70E₂ and 70F₂.

Incidentally, in FIG. 5, measurement stage MST is omitted and a liquidimmersion area that is formed by water Lq held in the space betweenmeasurement stage MST and tip lens 191 is shown by a reference code 14.Further, in FIG. 5, reference codes UP and LP indicate an unloadingposition where a wafer on wafer table WTB is unloaded and a loadingposition where a wafer is loaded on wafer table WTB that are setsymmetrical with respect to reference axis LV₀, respectively.Incidentally, unloading position UP and loading position LP may be thesame position.

In exposure apparatus 100 of the embodiment, as shown in FIGS. 5 and 7,a multipoint focal position detecting system (hereinafter, shortlyreferred to as a “multipoint AF system”) 90 by an oblique incidentmethod is arranged, which is composed of an irradiation system 90 a anda photodetection system 90 b, having a configuration similar to the onedisclosed in, for example, U.S. Pat. No. 5,448,332 and the like. In theembodiment, as an example, irradiation system 90 a is placed on the +Yside of the −X end portion of head unit 62E previously described, andphotodetection system 90 b is placed on the +Y side of the +X endportion of head unit 62F previously described in a state opposingirradiation system 90 a. Incidentally, multipoint AF system 90 is fixedto the lower surface of the mainframe holding projection unit PUpreviously described.

A plurality of detection points of the multipoint AF system 90 (90 a, 90b) are placed at a predetermined distance along the X-axis direction onthe surface to be detected. In the embodiment, the plurality ofdetection points are placed, for example, in the arrangement of a matrixhaving one row and M columns (M is a total number of detection points)or having two rows and N columns (N=M/2). In FIGS. 5 and 7, theplurality of detection points to which a detection beam is severallyirradiated are not individually shown, but are shown as an elongatedetection area (beam area) AF that extends in the X-axis directionbetween irradiation system 90 a and photodetection system 90 b. Becausethe length of detection area AF in the X-axis direction is set to aroundthe same as the diameter of wafer W, by only scanning wafer W in theY-axis direction once, position information (surface positioninformation) in the Z-axis direction across the entire surface of waferW can be measured.

As shown in FIG. 7, in the vicinity of both end portions of detectionarea AF of multipoint AF system 90 (90 a, 90 b), heads 72 a and 72 b,and 72 c and 72 d of surface position sensors for Z position measurement(hereinafter, shortly referred to as “Z heads”) are arranged each in apair, in symmetrical placement with respect to reference axis LV₀. Zheads 72 a to 72 d are fixed to the lower surface of the mainframe (notshown).

As Z heads 72 a to 72 d, for example, a head of an optical displacementsensor similar to an optical pickup used in a CD drive device is used. Zheads 72 a to 72 d irradiate measurement beams to wafer table WTB fromabove, and by receiving the reflected lights, measure the surfaceposition of wafer table WTB at the reflection points. Incidentally, inthe embodiment, a configuration is employed where the measurement beamsof the Z heads are reflected by the reflection grating configuring the Yscales 39Y₁ and 39Y₂ previously described.

Furthermore, as shown in FIG. 6, head units 62A and 62C previouslydescribed are respectively equipped with Z heads 76 _(j) and 74 _(i) (i,j=1 to 5), which are five heads each, at the same X position as Y heads65 _(j) and 64 _(i) (i, j=1 to 5) that head units 62A and 62C arerespectively equipped with, with the Y position shifted. In this case, Zheads 76 ₃ to 76 ₅ and 74 ₁ to 74 ₃, which are three heads each on theouter side belonging to head units 62A and 62C, respectively, are placedparallel to reference axis LH a predetermined distance away in the +Ydirection from reference axis LH. Further, Z heads 76 ₁ and 74 ₅, whichare heads on the innermost side belonging to head units 62A and 62C,respectively, are placed on the +Y side of projection unit PU, and theremaining Z heads 76 ₂ and 74 ₄ are placed on the −Y side of Y heads 65₂ and 64 ₄, respectively. And five Z heads 76 _(j) and 74 _(i), whichbelong to head unit 62A and 62C, respectively, are placed symmetric toeach other with respect to reference axis LV₀. Incidentally, as each ofthe Z heads 76 _(j) and 74 _(i), an optical displacement sensor headsimilar to Z heads 72 a to 72 d described above is employed.

The distance of the five Z heads 76 _(j) and 74 _(i) (to be moreaccurate, the irradiation point of the measurement beam generated by theZ heads on the scale) in the X-axis direction ti that are equipped ineach of head units 62A and 62C is set equal to distance WD of Y heads 65and 64 in the X-axis direction. Accordingly, on exposure and the like,of the respective five Y heads 65 _(j) and 64 _(i), at least one headeach constantly faces the corresponding Y scales 39Y₁ and 39Y₂.

Z heads 72 a to 72 d, Z heads 74 ₁ to 74 ₅, and Z heads 76 ₁ to 76 ₅described above connect to main controller 20 via a signalprocessing/selection device 160, as shown in FIG. 10. Main controller 20selects an arbitrary Z head from Z heads 72 a to 72 d, Z heads 74 ₁ to74 ₅, and Z heads 76 ₁ to 76 ₅ via signal processing/selection device160 and makes the head move into an operating state, and then receivesthe surface position information detected by the Z head which is in theoperating state via signal processing/selection device 160. In theembodiment, a surface position measurement system 180 that measurespositional information of wafer stage WST in the Z-axis direction andthe direction of inclination with respect to the XY plane is configured,including Z heads 72 a to 72 d, 74 ₁ to 74 ₅, and 76 ₁ to 76 ₅, andsignal processing/selection device 160.

Furthermore, in exposure apparatus 100 of the embodiment, as shown inFIG. 5, a periphery exposure unit 51 extending in the X-axis directionis placed in between a detection area (a beam area) AF of the multipointAF system and head units 62C and 62A. Periphery edge exposure unit 51 issupported in a suspended state via a support member (not shown) on thelower surface of the mainframe (not shown).

Periphery edge exposure unit 51 has a light source (not shown) whichemits light having substantially the same wavelength as illuminationlight IL, and an active mask (hereinafter appropriately shortly referredto as an active mask) 51 a (refer to FIG. 8) used for periphery edgeexposure on which the light from the light source is incident.Incidentally, instead of the light from the light source, for example,an optical fiber can be used to guide illumination light IL to activemask 51 a.

As shown in FIG. 5, the length of periphery edge exposure unit 51(active mask 51 a) is set somewhat longer than the diameter of wafer W.As an example, as shown in FIG. 8, active mask 51 a has a pair ofvariable shaped masks VM1 and VM2 on both ends in the X-axis direction.

As each of the variable shaped masks VM1 and VM2, as an example, amicromirror array which includes a plurality of micromirrors M_(ij)(refer to FIGS. 9A and 9B) placed in a matrix within an XY plane isused. This micromirror array is a movable micromirror formed using MEMStechnology on an integrated circuit made by a CMOS process. The mirrorsurface (reflection surface) of each micromirror can be inclined arounda predetermined axis (for example, an axis coinciding with a diagonalline of the micromirror) in a range of a predetermined angle, ±θ (θ is,for example, 3 degrees (or 12 degrees)), and by driving an electrodearranged on the lower portion of the mirror surface, the micromirror canhave two states which are “on (ON)” (−θ) and “off (OFF)” (+θ). Morespecifically, each variable shaped mask is equipped with a substratewhich becomes a base portion, a movable micromirror M_(ij) formed on thesubstrate, and an electrode which performs the on/off of eachmicromirror.

Each micromirror M_(ij) is set, as an example, either to a state (orposture) in which light from the light source is reflected toward waferW as shown in FIG. 9A, or a state (or posture) in which light from thelight source is reflected to a predetermined direction that does notmake the light from light source enter wafer W as shown in FIG. 9B by adrive signal supplied to the electrode. In the description below, theformer will be referred to as an on state (or an on posture) ofmicromirror M_(ij), and the latter will be referred to as an off state(or an off posture) of micromirror M_(i,j).

Main controller 20 controls each micromirror M_(ij) individually so thateach micromirror is either in an on state (or on posture) or an offstate (or off posture). Therefore, according to periphery edge exposureunit 51 of the embodiment, by moving wafer stage WST in the Y-axisdirection in a state where the center of wafer W in the X-axis directionsubstantially coincides with the center of periphery edge exposure unit51 in the longitudinal direction, an arbitrary position close to bothedges of wafer W in the X-axis direction can be exposed and an arbitrarypattern can be formed. More specifically, periphery edge exposure unit51 can form two irradiation areas for periphery edge exposure which arespaced apart in the X-axis direction, and the positions are movable atleast in the X-axis direction.

FIG. 10 shows the main configuration of the control system of exposureapparatus 100. The control system is mainly configured of maincontroller 20 composed of a microcomputer (or workstation) that performsoverall control of the entire apparatus. Incidentally, in FIG. 10,various sensors such as uneven illuminance measuring sensor 94, aerialimage measuring instrument 96 and wavefront aberration measuringinstrument 98 that are arranged at measurement stage MST arecollectively shown as a sensor group 99.

Next, a parallel processing operation that uses wafer stage WST andmeasurement stage MST in exposure apparatus 100 of the embodiment willbe described, based on FIGS. 14 to 24. Incidentally, during theoperation below, main controller 20 performs the open/close control ofeach valve of liquid supply unit 5 of local liquid immersion unit 8 andliquid recovery unit 6 in the manner previously described, and water isconstantly filled on the outgoing surface side of tip lens 191 ofprojection optical system PL. However, in the description below, for thesake of simplicity, the explanation related to the control of liquidsupply unit 5 and liquid recovery unit 6 will be omitted. Further, manydrawings are used in the operation description hereinafter, however,reference codes may or may not be given to the same member for eachdrawing. More specifically, the reference codes written are differentfor each drawing, however, such members have the same configuration,regardless of the indication of the reference codes. The same can besaid for each drawing used in the description so far.

Prior to describing the parallel processing operation, the size andarrangement of shot areas formed on wafer W subject to exposure, or morespecifically, a shot map and the like of wafer W will now be described.FIG. 11 shows a planar view of wafer W. The effective exposure area(corresponding to an area inside a circular external form in FIG. 11) onwhich resist of wafer W has been applied is divided into a large numberof shot areas Sj (In FIG. 11, j=1-76). And, as an example, shot area Sjis to be a shot area where two devices, which are identical devices(chips), are formed.

In the embodiment, 16 shot areas (S2, S4, S6, S18, S20, S22, S24, S26,S51, S53, S55, S57, S59, S71, S73, S75) which are indicated in black inFIG. 12 are to be specified as sample shot areas (alignment shot areas)on wafer alignment (EGA: Enhanced Global Alignment) by an operator. Ofthe 16 sample shot areas described above, three shot areas (S71, S73,S75) are a first alignment shot area, five shot areas (S51, S53, S55,S57, S59) are a second alignment shot area, five shot areas (S18, S20,S22, S24, S26) are a third alignment shot area, and three shot areas(S2, S4, S6) are a fourth alignment shot area.

Further, in the embodiment, as shown in FIG. 13, in the 12 peripheryshots (S1, S7, S8, S16, S17, S27, S50, S60, S61, S69, S70, S76) of waferW, half of the areas (S1 a, S7 a, S8 a, S16 a, S17 a, S27 a, S50 a, S60a, S61 a, S69 a, S70 a, S76 a) on the edge side of wafer W are eachsubject to periphery edge exposure (hereinafter referred to as,periphery edge exposure area).

The parallel processing operation using both stages MST and WST whichwill be described below, is performed, as a whole, in a proceduresimilar to the parallel processing operation disclosed in, for example,the pamphlet of international Publication No. 2007/097379 (and thecorresponding U.S. Patent Application Publication 2008/0088843).

FIG. 14 shows a state in which an exposure by the step-and-scan methodof wafer W mounted on wafer stage WST is performed. This exposure isperformed by repeating a movement between shots in which wafer stage WSTis moved to a scanning starting position (acceleration staring position)to expose each shot area on wafer W and scanning exposure in which thepattern formed on reticle R is transferred onto each shot area by thescanning exposure method, based on results of wafer alignment (EGA:Enhanced Global Alignment) and the like which has been performed priorto the beginning of exposure. Further, exposure is performed in thefollowing order, from the shot area located on the −Y side on wafer W tothe shot area located on the +Y side. Incidentally, exposure isperformed in a state where liquid immersion area 14 is formed in betweenprojection unit PU and wafer W.

During the exposure described above, the position (including theposition (θz rotation) in the θz direction) of wafer stage WST in the XYplane is controlled by main controller 20, based on measurement resultsof a total of three encoders which are the two Y encoders 70A and 70C,and one of the two X encoders 70B and 70D. In this case, the two Xencoders 70B and 70D are made up of two X heads 66 that face X scale39X₁ and 39X₂, respectively, and the two Y encoders 70A and 70C are madeup of Y heads 65 and 64 that face Y scales 39Y₁ and 39Y₂, respectively.Further, the Z position and the θy rotation (rolling) of wafer stage WSTare controlled, based on measurement results of Z heads 74 _(i) and 76_(j), which respectively belong to head units 62C and 62A facing the endsection on one side and the other side of the surface of wafer table WTBin the X-axis direction, respectively. The θx rotation (pitching) ofwafer stage WST is controlled based on measurement values of Yinterferometer 16. Incidentally, in the case three or more Z headsincluding Z head 74 _(i) and 76 _(j) face the surface of the secondwater repellent plate 28 b of wafer table WTB, it is also possible tocontrol the position of wafer stage WST in the Z-axis direction, the θyrotation (rolling), and the θx rotation (pitching), based on themeasurement values of Z heads 74 _(i), 76 _(j) and the other one Z head.In any case, the control (more specifically, the focus leveling controlof wafer W) of the position of wafer stage WST in the Z-axis direction,the θy rotation, and the θx rotation is performed, based on results of afocus mapping performed beforehand.

At the position of wafer stage WST shown in FIG. 14, while X head 66 ₅(shown circled in FIG. 14) faces X scale 39X₁, there are no X heads 66that face X scale 39X₂. Therefore, main controller 20 uses one X encoder70B and two Y encoders 70A and 70C so as to perform position (X, Y, θz)control of wafer stage WST. In this case, when wafer stage WST movesfrom the position shown in FIG. 14 to the −Y direction, X head 66 ₅moves off of (no longer faces) X scale 39X₁, and X head 66 ₄ (showncircled in a broken line in FIG. 14) faces X scale 39X₂ instead.Therefore, main controller 20 switches to a control (hereinafter shortlyreferred to as stage control, as appropriate) of the position (andspeed) of wafer stage WST using one X encoder 70D and two Y encoders 70Aand 70C.

Further, when wafer stage WST is located at the position shown in FIG.14, Z heads 74 ₃ and 76 ₃ (shown circled in FIG. 14) face Y scales 39Y₂and 39Y₁, respectively. Therefore, main controller 20 performs position(Z, θy) control of wafer stage WST using Z heads 74 ₃ and 76 ₃. In thiscase, when wafer stage WST moves from the position shown in FIG. 14 tothe +X direction, Z heads 74 ₃ and 76 ₃ move off of (no longer faces)the corresponding Y scales, and Z heads 74 ₄ and 76 ₄ (shown circled ina broken line in the drawing) respectively face Y scales 39Y₂ and 39Y₁instead. Therefore, main controller 20 switches the stage control to acontrol that uses Z heads 74 ₄ and 76 ₄.

In this manner, main controller 20 performs stage control byconsistently switching the encoders and the Z heads to be used dependingon the position coordinate of wafer stage WST.

Incidentally, independent from the position measurement of wafer stageWST described above using the measuring instruments described above,position (X, Y, Z, θx, θy, θz) measurement of wafer stage WST usinginterferometer system 118 is constantly performed. In this case, the Xposition and θz rotation quantity (yawing amount) of wafer stage WST aremeasured using X interferometers 126, 127, or 128, the Y position, theθx rotation quantity, and the θz rotation quantity are measured using Yinterferometer 16, and the Y position, the Z position, the θy rotationquantity, and the θz rotation quantity are measured using Zinterferometers 43A and 43B that constitute interferometer system 118.Of X interferometers 126, 127, and 128, one interferometer is usedaccording to the Y position of wafer stage WST. As indicated in FIG. 14,X interferometer 126 is used during exposure. The measurement results ofinterferometer system 118 except for the pitching amount (θx rotationquantity) are used for position control of wafer stage WST secondarily,or in the case of backup which will be described later on, or whenmeasurement using encoder system 150 and/or surface position measurementsystem 180 cannot be performed.

When exposure of wafer W has been completed, main controller 20 driveswafer stage WST toward unload position UP. On this drive, wafer stageWST and measurement stage MST which were apart during exposure come intocontact or move close to each other with a clearance of around 300 μm inbetween, and shift to a scrum state. In this case, the −Y side surfaceof FD bar 46 on measurement table MTB and the +Y side surface of wafertable WTB come into contact or move close together. And by moving bothstages WST and MST in the −Y direction while maintaining the scrumcondition, liquid immersion area 14 formed under protection unit PUmoves to an area above measurement stage MST. For example, FIGS. 15 and16 show the state after the movement.

When wafer stage WST moves further to the −Y direction and moves offfrom the effective stroke area (the area in which wafer stage WST movesat the time of exposure and wafer alignment), all the X heads and Yheads that constitute encoder system 150, and all the Z heads thatconstitute surface position measurement system 180 move off from thecorresponding scales on wafer table WTB. Therefore, stage control basedon the measurement results of encoder system 150 and surface positionmeasurement system 180 is no longer possible. Thus, just before thestage control based on the measurement results of encoder system 150 andsurface position measurement system 180 is no longer possible, maincontroller 20 switches the control from a stage control based on themeasurement results of both systems 150 and 180 to a stage control basedon the measurement results of interferometer system 118. In this case,of the three X interferometers 126, 127, and 128, X interferometer 128is used.

Then, as shown in FIG. 15, wafer stage WST releases the scrum state withmeasurement stage MST, and then moves to unloading position UP. Afterthe movement, main controller 20 unloads wafer W on wafer table WTB. Andthen, as shown in FIG. 16, wafer stage WST is driven in the +X directionto loading position LP, and the next wafer W is loaded on wafer tableWTB.

In parallel with these operations, main controller 20 performs Sec-BCHK(a secondary base line check) in which position adjustment of FD bar 46supported by measurement stage MST in the XY plane and baselinemeasurement of the four secondary alignment system AL2 ₁ to AL2 ₄ areperformed. Sec-BCHK is performed on an interval basis for every waferexchange. In this case, in order to measure the θz rotation quantity ofFD bar 46, Y encoder 70E₂ and 70F₂ describe above are used.

Next, as shown in FIG. 17, main controller 20 drives wafer stage WST andpositions reference mark FM on measurement plate 30 within a detectionfield of primary alignment system AL1, and performs the former processof a Pri-BCHK (a primary baseline check) in which the reference positionis decided for baseline measurement of alignment system AL1, and AL2 ₁to AL2 ₄.

On this process, as shown in FIG. 17, two Y heads 68 ₂ and 67 ₃ and oneX head 66 ₁ (shown circled in the drawing) come to face Z scales 39Y₁and 39Y₂, and X scale 39X₂, respectively. Then, main controller 20switches the stage control from a control using interferometer system118, to a control using encoder system 150 (encoders 70E₁, 70F₁, and70D). Interferometer system 118 is used secondarily again, except formeasurement of the θx rotation quantity. Incidentally, of the three Xinterferometers 126, 127, and 128, X interferometer 127 is used.

Next, while controlling the position of wafer stage WST based on themeasurement values of the three encoders described above, maincontroller 20 begins the movement of wafer stage WST in the +Y directiontoward a position where an alignment mark arranged in three firstalignment shot areas is detected.

Then, when wafer stage WST reaches the position shown in FIG. 18, maincontroller 20 stops wafer stage WST. Prior to this opera ion, maincontroller 20 activates (turns ON) Z heads 72 a to 72 d and startsmeasurement of the Z-position and the tilt amount (the θy rotationquantity) of wafer table WTB at the point in time when all of or part ofZ heads 72 a to 72 d face(s) wafer table WTB, or before that point intime.

After wafer stage WST is stopped, main controller 20 detects alignmentmarks arranged in the three first alignment shot areas substantially atthe same time and also individually (refer to the star-shaped marks inFIG. 18), using primary alignment system AL1, and secondary alignmentsystems AL2 ₂ and AL2 ₃, and makes a link between the detection resultsof the three alignment systems AL1, AL2 ₂, and AL2 ₃ and the measurementvalues of the three encoders above at the time of the detection, andstores them in memory (not shown).

As described above, in the embodiment, the shift to the contact state(or proximity state) between measurement stage MST and wafer stage WSTis completed at the position where detection of the alignment marks ofthe first alignment shot area is performed, and from the position, maincontroller 20 begins to move both stages WST and MST in the +Y direction(step movement toward the position for detecting the alignment marksarranged in the five second alignment shot areas) in the contact state(or proximity state). Prior to starting the movement of both stages WSTand MST in the +Y direction, as shown in FIG. 18, main controller 20begins irradiation of a detection beam from irradiation system 90 of themultipoint AF system (90 a, 90 b) to wafer table WTB. Accordingly, adetection area of the multipoint AF system is formed on wafer table WTB.

Then, when both stages WST and MST reach the position shown in FIG. 19during the movement of both stages WST and MST in the +Y direction, maincontroller 20 performs the former process of the focus calibration inwhich the relation between the measurement values (surface positioninformation on one side and the other side of wafer table WTB in theX-axis direction) of Z heads 72 a, 72 b, 72 c, and 72 d in a state wherethe center line of wafer table WTB coincides with reference axis LV₀,and the detection results (surface position information) of the surfaceof measurement plate 30 by the multipoint AF system (90 a, 90 b) isobtained. At this point, liquid immersion area 14 is formed on the uppersurface of FD bar 46.

Then, when both stages WST and MST move further in the +Y directionwhile maintaining the contact state (or proximity state) and reach theposition shown in FIG. 20, the alignment marks arranged in the fivesecond alignment shot areas are detected (refer to the star-shaped marksin FIG. 20) individually, substantially at the same time, using the fivealignment systems AL1, and AL2 ₁ to AL2 ₄, and a link is made betweenthe detection results of the five alignment systems AL1, and AL2 ₁ toAL2 ₄ and the measurement values of the three encoders measuring theposition of wafer stage WST in the XY plane at the time of thedetection, and then is stored in memory (not shown). At this point, maincontroller 20 controls the position within the XY plane of wafer stageWST based on the measurement values of X head 66 ₂ (X linear encoder70D) that faces X scale 39X₂ and Y linear encoders 70E₁ and 70F₁.

Further, after the detection of the alignment marks arranged in the fivesecond alignment shot areas described above ends, main controller 20starts the movement in the +Y direction again of both stages WST and MSTin the contact state (or proximity state), and at the same time, startsthe focus mapping in which positional information (surface positioninformation) related to the wafer W surface in the Z-axis direction isdetected using Z heads 72 a to 72 d and the multipoint AF system (90 a,90 b), as shown in FIG. 20.

Then, after beginning the focus mapping until both stages WST and MSTreach the position shown in FIG. 21, by individually controlling theON/OFF of each micromirror M_(ij)that constitute the two variable shapedmasks VM1 and VM2 of periphery edge exposure unit 51 according to the Yposition of wafer stage WST measured by Y linear encoders 70E₁ and 70F₁,main controller 20 sequentially exposes periphery edge exposure areasS70 a and S76 a, S61 a and S69 a, and S50 a and S60 a, as shown in FIGS.25A, 25B, and 25C. In this case, main controller 20 can perform overallexposure of each periphery edge exposure area using periphery edgeexposure unit 51, or a predetermined pattern can be formed.

Then, when both stages WST and MST reach the position shown in FIG. 21where measurement plate 30 is located directly below projection opticalsystem PL, main controller 20 performs the latter process of focuscalibration as in the description below, in a state continuing thecontrol of Z position of wafer stage WST (measurement plate 30) thatuses the surface position information measured by Z heads 72 a, 72 b, 72c, and 72 d as a reference, without switching the Z head used forposition (Z position) control of wafer stage WST in the optical axisdirection of projection optical system PL to Z heads 74 _(i) and 76_(j). More specifically, while controlling the position of measurementplate 30 (wafer stage WST) in the optical axis direction of projectionoptical system PL (the Z position) using surface position informationmeasured by Z heads 72 a to 72 d as a reference, main controller 20measures an aerial image of a measurement mark formed on reticle R or ona mark plate (not shown) on reticle stage RST by a Z direction scanningmeasurement whose details are disclosed in, for example, the pamphlet ofInternational Publication No. 2005/124834 (and the corresponding U.S.Patent Application Publication No. 2008/030715) and the like, usingaerial image measuring device 45, and based on the measurement results,measures the best focus position of projection optical system PL. Duringthe Z direction scanning measurement described above, main controller 20takes in measurement values of a pair of Z heads 74 ₃ and 76 ₃ whichmeasure the surface position information at end portions on one side andthe other side of wafer table WTB in the X-axis direction, insynchronization with taking in output signals from aerial imagemeasuring device 45. Then, main controller 20 stores the values of Zheads 74 ₃ and 76 ₃ corresponding to the best focus position ofprojection optical system PL in memory (not shown). Incidentally, thereason why the position (Z position) related to the optical axisdirection of projection optical system PL of measurement plate 30 (waferstage WST) is controlled using the surface position information measuredin the latter process of the focus calibration by Z heads 72 a to 72 dis because the latter process of the focus calibration is performedduring the focus mapping previously described.

Further, main controller 20 performs the latter process of Pri-BCHK asfollows, around the time of the latter process of focus calibrationdescribed above. More specifically, main controller 20 measures aprojection image (aerial image) of a pair of measurement marks onreticle R projected by projection optical system PL, respectively, usingaerial image measuring device 45, in a method similar to the onedisclosed in, for example, U.S. Patent Application Publication No.2002/0041377 and the like, by an aerial image measurement operation ofthe slit scan method using a pair of aerial image measurement slitpatterns SL, and the measurement results (aerial image intensityaccording to the XY position of wafer table WTB) are stored in memory.On this latter process of Pri-BCHK, the position of wafer table WTB inthe XY plane is controlled based on X head 66 ₄ (encoder 70D) whichfaces X scale 39X₂, and two Y heads 67 ₃ and 68 ₂ (encoders 70E₁ and70F₁) (or Y heads 65 _(j) and 64 _(i) (encoders 70A and 70C)) that faceY scales 39Y₁ and 39Y₂.

Then, based on the results of the former process of Pri-BCHK and theresults of the latter process of the Pri-BCHK described above, maincontroller 20 computes the baseline of primary alignment system AL1.With such operation, main controller 20 obtains the offset at therepresentative detection point of the multipoint AF system (90 a, 90 b)based on the results of the former process and the latter process offocus calibration previously described, and stores the offset in aninternal memory. And, on reading mapping information obtained from theresults of focus mapping at the time of exposure, main controller 20 isto add the offset to the mapping information.

Incidentally, in the state of FIG. 21, the focus mapping is beingcontinued.

When wafer stage WST reaches the position shown in FIG. 22 by movementin the +Y direction of both stages WST and MST in the contact state (orproximity state) described above, main controller 20 stops wafer stageWST at that position, while making measurement stage MST continue themovement in the +Y direction. Then, main controller 20 detects thealignment mark arranged in the five second alignment shot areassubstantially at the same time as well as individually (refer to thestar-shaped marks in FIG. 22), using the five alignment systems AL1, andAL2 ₁ to AL2 ₄, and makes a link between the detection results of thefive alignment systems AL1, and AL2 ₁ to AL2 ₄ and the measurementvalues of the three encoders at the time of the detection, and thenstores them in the internal memory. Also at this point in time, thefocus mapping is being continued.

Meanwhile, after a predetermined period of time from the suspension ofwafer stage WST described above, measurement stage MST and wafer stageWST move from the contact state (or proximity state) into a separationstate. After moving into the separation state, main controller 20 stopsthe movement of measurement stage MST when measurement stage MST reachesan exposure start waiting position where measurement stage MST waitsuntil exposure is started.

Next, main controller 20 starts the movement of wafer stage WST in the+Y direction toward a position where the alignment mark arranged in thethree fourth alignment shots are detected. At this point in time, thefocus mapping is being continued. Meanwhile, measurement stage MST iswaiting at the exposure start waiting position described above.

Then, after completing the focus calibration previously described, untilboth stages WST and MST reach the position shown in FIG. 23 afterbeginning the movement in the +Y direction, main controller 20sequentially exposes periphery edge exposure areas S17 a and S27 a, andS8 a and S16 a, as shown in FIGS. 25D and 25E, by individuallycontrolling the ON/OFF of each micromirror M_(ij) that constitute thetwo variable shaped masks VM1 and VM2 of periphery edge exposure unit 51according to the Y position of wafer stage WST measured by Y linearencoders 70E₁ and 70F₁. In this case as well, main controller 20 canperform overall exposure of each periphery edge exposure area usingperiphery edge exposure unit 51, or a predetermined pattern can beformed.

Then, when wafer stage WST reaches the position shown in FIG. 23, maincontroller 20 immediately stops wafer stage WST, and almostsimultaneously and individually detects the alignment marks arranged inthe three fourth alignment shot areas on wafer W (refer to star-shapedmarks in FIG. 23) using primary alignment system AL1 and secondaryalignment systems AL2 ₂ and AL2 ₃, links the detection results of threealignment systems AL1, AL2 ₂ and AL2 ₃ and the measurement values of thethree encoders out of the four encoders at the time of the detection,and stores them in memory (not shown). Also at this point in time, thefocus mapping is being continued, and measurement stage MST is stillwaiting at the exposure start waiting position. Then, main controller 20computes an array information (coordinate values) of all the shot areason wafer W on a coordinate system which is set by the measurement axesof the four encoders 70E₁, 70E₂, 70B, and 70D described above of theencoder system, by performing a statistical computation, which isdisclosed in, for example, Kokai (Japanese Unexamined Patent ApplicationPublication) No. 61-044429 and the like, using the detection results ofa total of 16 alignment marks which have been obtained in the mannerdescribed above and the corresponding measurement values of theencoders.

Next, main controller 20 continues the focus mapping while moving waferstage WST in the +Y direction again. During the movement of wafer stageWST in the +Y direction, main controller 20 sequentially exposesperiphery edge exposure areas S1 a and S7 a, as shown in FIG. 25F, byindividually controlling the ON/OFF of each micromirror M_(ij) thatconstitute the two variable shaped masks VM1 and VM2 of periphery edgeexposure unit 51 according to the Y position of wafer stage WST measuredby Y linear encoders 70E₁ and 70F₁. In this case as well, maincontroller 20 can perform overall exposure of each periphery edgeexposure area using periphery edge exposure unit 51, or a predeterminedpattern can be formed. This completes the periphery edge exposure ofwafer W, and as shown in FIG. 26, periphery edge exposure areas S1 a, S7a, S8 a, S16 a, S17 a, S27 a, S50 a, S60 a, S61 a, S69 a, S70 a, and S76a each become an area that has undergone exposure.

Then, when wafer stage WST moves further in the +Y direction, and thedetection beam from the multipoint AF system (90 a, 90 b) moves off ofthe wafer W surface as shown in FIG. 24, main controller 20 ends thefocus mapping.

After the focus mapping has been completed, main controller 20 moveswafer stage WST to a scanning starting position (exposure startingposition) for exposure of the first shot on wafer W, and during themovement, main controller 20 switches the Z heads used for control ofthe Z position and the θy rotation of wafer stage WST from Z heads 72 ato 72 d to Z heads 74 _(i) and 74 _(j) while maintaining the Z position,the θy rotation, and the θx rotation of wafer stage WST. Then,immediately after this switching, based on the results of the waferalignment (EGA) previously described and the latest baselines and thelike of the five alignment systems AL1 and AL2 ₁ to AL2 ₄, maincontroller 20 performs exposure by a step-and-scan method in a liquidimmersion exposure, and sequentially transfers a reticle pattern to aplurality of shot areas on wafer W. Hereinafter, a similar operation isexecuted repeatedly.

As discussed in detail above, according to exposure apparatus 100 of theembodiment, while wafer stage WST moves linearly in the Y-axisdirection, surface position information of the wafer W surface isdetected by multipoint AF system (90 a, 90 b) whose plurality ofdetection points is set in the X-axis direction at a predeterminedinterval, and alignment marks having different positions on wafer W aredetected by a plurality of alignment systems AL1, and AL2 ₁ to AL2 ₄whose detection area is arranged in a line along the X-axis direction,and furthermore, periphery edge exposure of wafer W is performed byperiphery edge exposure unit 51. More specifically, by wafer stage WST(wafer W) linearly passing the plurality of detection points (detectionarea AF) of the multipoint AF system (90 a, 90 b), the detection area ofthe plurality of alignment systems AL1, and AL2 ₁ to AL2 ₄, and belowperiphery edge exposure unit 51, three operations which are detection ofsurface position information of substantially the entire surface ofwafer W, detection of all the alignment marks (for example, alignmentmarks in the alignment area on EGA) which should be detected on wafer W,and periphery edge exposure of wafer W are completed. Therefore,throughput can be improved remarkably when compared with the case whendetection operation of the alignment marks, detection operation of thesurface position information (focus information) and periphery edgeexposure operation are performed independently (separately). Morespecifically, because it is possible to make the time required forperiphery edge exposure operation approximately overlap the waferalignment operating time, the periphery edge exposure operation hardlydecreases the throughput.

Further, according to the embodiment, positional information of wafertable WTB in the XY plane is measured with high precision without beingaffected by air fluctuation and the like by encoder system 150 whichincludes encoders 70A to 70F whose short-term stability of measurementis good, and positional information of wafer table WTB in the Z-axisdirection orthogonal to the XY plane is also measured with highprecision without being affected by air fluctuation and the like bysurface position measurement system 180 which includes Z heads 72 a to72 d, 74 ₁ to 74 ₅, 75 ₁ to 76 ₅ and the like. In this case, becauseboth encoder system 150 and surface position measurement system 180measure the wafer table WTB upper surface directly, a simple and directposition control of wafer table WTB, or consequently, wafer W becomespossible.

Further, according to the embodiment, on the focus mapping previouslydescribed, main controller 20 simultaneously activates surface positionmeasurement system. 180 and multipoint AF system (90 a, 90 b), and thedetection results of multipoint AF system (90 a, 90 b) are convertedinto data which uses the measurement results of surface positionmeasurement system 180 as a reference. Accordingly, by acquiring thisconversion data in advance, surface position control of wafer W becomespossible by measuring only positional information of wafer table WTB inthe Z-axis direction and positional information in a tilt direction withrespect to the XY plane using surface position measurement system 180,without acquiring surface position information of wafer W. Accordingly,in the embodiment, although the working distance between tip lens 191and wafer W surface is narrow, focus leveling control of wafer W onexposure can be performed with good precision, without any trouble.

Further, according to the embodiment, as described above, because wafertable WTB, or consequently, the surface position of wafer W can becontrolled with high precision, exposure with high precision with hardlyany exposure defect due to surface position control error becomespossible, which makes it possible to form an image of a pattern on waferW without the image being blurred due to defocus.

Further, according to the embodiment, the placement distance in theX-axis direction of the plurality of Y heads 64 and 65 whose measurementdirection is in the Y-axis direction is shorter than the width of Yscales 39Y₁ and 39Y₂ in the X-axis direction, and the placement distancein the Y-axis direction of the plurality of Y heads 66 whose measurementdirection is in the X-axis direction is shorter than the width of Xscales 39X₁ and 39X₂ in the Y-axis direction. Therefore, on moving wafertable WTB (wafer stage WST), the Y position of wafer table WTB (waferstage WST) can be measured, based on the measurement values of Y linearencoder 70A or 70C which irradiates a detection light (beam) on Y scale39Y₁ or 39Y₂ while sequentially switching the plurality of Y heads 64and 65, and concurrently, the X position of wafer table WTB (wafer stageWST) can be measured, based on the measurement values of X linearencoder 70B or 70D which irradiates a detection light (beam) on X scale39X₁ or 39X₂ while sequentially switching the plurality of X heads 66.

Further, in the embodiment above, while the example has been describedin which the alignment systems (AL1, and AL2 ₁ to AL₄) multipoint AFsystem 90, and periphery edge exposure unit 51 were placed away from theexposure position (the position below projection unit PU where liquidimmersion area 14 is formed) where exposure of wafer W is performed inthe Y-axis direction, the present invention is not limited to this. Forexample, one of the alignment systems (AL1, and AL2 ₁ to AL2 ₄) andmultipoint AF system 90 does not have to be placed at the positiondescribed above. Even in such a case, the periphery edge exposure of thewafer can be performed concurrently while moving wafer stage WST in theY-axis direction toward the exposure position, due to the measurement ofthe wafer by the other measurement device. Accordingly, because it ispossible to make the time required for periphery edge exposure operationoverlap the time for other operations, the throughput can be improved.

Or both the alignment systems (AL1, and AL2 ₁ to AL2 ₄) and multipointAF system 90 do not have to be placed at the position described above.However, in this case, a measurement device which performs some kind ofmeasurement on the wafer should be placed at a position similar to thealignment systems (AL1, and AL2 ₁ to AL₄) and the multipoint AF system(90 a, 90 b).

Incidentally, in the embodiment above, the case has been described wherethe pair of Y scales 39Y₁ and 39Y₂ used for measuring the position ofwafer stage WST in the Y-axis direction while the pair of X scales 39X₁and 39X₂ used for measuring the position in the X-axis direction arearranged, and corresponding to this, the pair of head units 62A and 62Care placed on one side and the other side of projection optical systemPL in the X-axis direction, while two head units 62B and 62D are placedon one side and the other side of projection optical system PL in theY-axis direction. However, the present invention is not limited to this,and of the Y scales 39Y₁ and 39Y₂ used to measure the position in theY-axis direction and X scales 39X₁ and 39X₂ used to measure the positionin the X-axis direction, at least one of the Y and X scales does nothave to be a pair and can have only one scale arranged on wafer tableWTB, or of the pair of head units 62A and 62C and two head units 62B and62D, at least one of the two group of heads can have only one headarranged. Further, the extending direction of the scale and theextending direction of the head unit are not limited to orthogonaldirection such as the X-axis direction and the Y-axis direction of theembodiment, and can be directions that intersect each other.

Further, in the embodiment above, while head units 62A to 62D had aplurality of heads placed at predetermined distance, a single head canalso be employed, equipped with a light source which emits a light beamthat extends narrowly in the pitch direction of the Y scale or the Xscale and multiple light receiving elements arranged without a gap inthe pitch direction of the Y scale or the X scale that receive thereflected light (diffraction light) from the Y scale or the X scale(diffraction grating) of the light beam.

Incidentally, in the embodiment above, while the case has been describedwhere the present invention was applied to an exposure apparatusequipped with all sections such as wafer stage WST, measurement stageMST, alignment systems (AL1, and AL2 ₁ to AL2 ₄), multipoint AF system(90 a, 90 b), Z sensor, interferometer system 118, the encoder system(70A to 70F) and the like, the present invention is not limited to this.For example, the present invention can also be applied to an exposureapparatus which does not have measurement stage MST arranged. Thepresent invention can be applied, as long as the exposure apparatus isequipped with a wafer stage (movable body) and some of the componentsbesides the wafer stage. More specifically, the present invention can beapplied as long as a measurement device, which can perform some kind ofa measurement on the wafer, is arranged at a position similar to thealignment systems (AL1, and AL2 ₁ to AL₄) and multipoint AF system (90a, 90 b) described above, away from the exposure position where exposureof wafer W is performed.

Incidentally, in the embodiment above, while the example has beendescribed where periphery edge exposure unit 51 was placed on theprojection unit PU side of alignment systems (AL1, and AL2 ₁ to AL₄)(and multipoint AF system (90 a, 90 b)), as well as this, the peripheryedge exposure unit can be placed at the unloading position UP andloading position LP side of alignment systems (AL1, and AL2 ₁ to AL₄)(and multipoint AF system (90 a, 90 b)).

Further, in the embodiment above, while the example has been describedwhere the periphery edge exposure of wafer W was performed while waferstage WST was proceeding from loading position LP to the exposureposition (projection unit PU), as well as this, the periphery edgeexposure can be performed while wafer stage WST is returning from theexposure position. (projection unit PU) to unloading position UP, or theperiphery edge exposure of one wafer can be performed on both theproceeding and returning path.

Further, in the embodiment above, while the example has been describedwhere periphery edge exposure unit 51 which can irradiate twoirradiation areas for periphery edge exposure spaced apart in the X-axisdirection is used, however, the configuration of the periphery edgeexposure unit is not limited to this. However, it is desirable that theperiphery edge exposure unit has a plurality of irradiation areas whoseposition at least in the X-axis direction is variable, as in peripheryedge exposure unit 51 described above.

Further, in the embodiment above, the case has been described where bywafer stage WST (wafer W) linearly passing the plurality of detectionpoints (detection area AF) of the multipoint AF system (90 a, 90 b), thedetection area of the plurality of alignment systems AL1, and AL2 ₁ toAL2 ₄, and below periphery edge exposure unit 51, three operations whichare detection of surface position information of substantially theentire surface of wafer W, detection of all the alignment marks whichshould be detected on wafer W, and periphery edge exposure of wafer Ware completed. However, as well as this, at least a part of theperiphery edge exposure operation can be performed in parallel with themovement of wafer stage WST (wafer W) from the loading position to theexposure position. In this case, when at least a part of the measurementoperation (including mark detection and the like) is performed inparallel furthermore, the throughput can be further improved. Morespecifically, other issues are not essential as long as at least a partof the periphery edge exposure operation is performed during themovement of wafer stage WST (wafer W) from the loading position to theexposure position.

Further, in the embodiment above, while the case has been describedwhere measurement system 200 includes both of interferometer system 118and encoder system 150, as well as this, the measurement system caninclude only one of interferometer system 118 and encoder system 150.

A Second Embodiment

Next, a second embodiment of the present invention will he described,referring to FIGS. 27 to 39.

FIG. 27 schematically shows a configuration of an exposure apparatus 500in the second embodiment. Exposure apparatus 500 is a projectionexposure apparatus by the step-and-scan method, or a so-called scanner.

Exposure apparatus 500 is equipped with an illumination system 10, areticle stage RST, a projection unit PU, a stage device 50 having awafer stage WST and a measurement stage MST, and a control system ofthese parts and the like. In FIG. 27, a wafer W is mounted on waferstage WST. When compared with exposure apparatus 100 of the firstembodiment, exposure apparatus 500 is configured similar to exposureapparatus 100 of the first embodiment except for the point that insteadof wafer table WTB previously described, a wafer table WTB′ is used, andthe configuration of encoder system 150 is different. Hereinafter, thedescription will be made referring mainly to the differences, and thesame reference numerals will be used for the same or similar sections asin the first embodiment previously described, and the descriptionthereabout will be brief or omitted. Further, in order to simplify thedescription, explanation on the configuration and the like related toperiphery edge exposure of wafer W and focus leveling control will beomitted.

Similar to the first embodiment previously described, stage device 50 isequipped with wafer stage WST and measurement stage MST placed on baseboard 12, as shown in FIG. 27. Stage device 50, furthermore, is equippedwith a measurement system 200 which measures positional information ofboth stages WST and MST, a stage drive system 124 and the like (neitherare shown in FIG. 27, refer to FIG. 32) which drives and both stages WSTand MST. Measurement system 200 includes an interferometer system 118and an encoder system 150, as shown in FIG. 32.

Wafer stage WST includes a stage main section 91, and a wafer table WTB′that is mounted on stage main section 91. Wafer table WTB′ and stagemain section 91 are configured drivable in directions of six degrees offreedom (X, Y, Z, θx, θy, and θz) with respect to base board 12 by adrive system, including a linear motor and a Z leveling mechanism(including a voice coil motor and the like).

In the center of the upper surface of wafer table WTB′, a wafer holder(not shown) is arranged which holds wafer W by vacuum suction or thelike. On the outer side of the wafer holder (mounting area of thewafer), as shown in FIG. 28, a plate (a liquid repellent plate) 28′ isarranged that has a circular opening one size larger than the waferholder formed in the center, and also has a rectangular outer shape(contour). A liquid repellent treatment against liquid Lq is applied tothe surface of plate 28′. Incidentally, plate 28′ is installed so thatits entire surface, or a part of its surface, becomes flush with thesurface of wafer W.

Plate 28′ is located in the center of the X-axis direction of wafertable WTB, and has a first liquid repellent area 28 a′ having arectangular outer shape (contour) with the circular opening describedabove formed in the center, and a rectangular pair of second liquidrepellent areas 28 b′ positioned on the +X side end and −X side end ofwafer table WTB in the X-axis direction with the first liquid repellentarea 28 a′ in between. Incidentally, in the second embodiment, becausewater will be used as liquid Lq, hereinafter the first liquid repellentarea 28 a′ and the second liquid repellent area 28 b′ will also referredto as a first water repellent plate 28 a′ and a second water repellentplate 28 b′.

Near the end on the +Y side of the first water repellent plate 28 a′, afiducial mark FM, and a measurement plate 30 on which a pair of aerialimage measurement slit patterns (slit-shaped measurement patterns) areformed, is arranged. In correspondence with each aerial imagemeasurement slit pattern SL, a light-transmitting system (not shown) isarranged, which guides illumination light IL passing through the slitpatterns outside wafer stage WST, or to be more specific, to thephotodetection system (not shown) previously described arranged inmeasurement table MTB (and stage main section 92). More specifically,also in the embodiment, an aerial image measuring unit 45 (refer to FIG.32) is configured in a state where wafer stage WST and measurement stageMST are in proximity within a predetermined distance in the Y-axisdirection (including a contact state), and illumination lights IL thathas been transmitted through each aerial image measurement slit patternSL of measurement plate 30 on wafer stage WST are guided by eachlight-transmitting system (not shown) and are received bylight-receiving elements of each photodetection system (not shown)within measurement stage MST.

On the pair of second water repellent plates 28 b′, moving scales for anencoder system (to be described later) are formed. To enter the details,on the second pair of water repellent plates 28 b′, moving scales 39Aand 39B are formed, respectively. Moving scales 39A and 39B are eachconfigured of a reflection type two-dimensional diffraction grating,which is, for example, a diffraction grating having a periodic directionin the Y-axis direction and a diffraction grating having a periodicdirection in the X-axis direction combined. The pitch of the grid linesof the two-dimensional diffraction gratings is set, for example, to 1μm, for both the Y-axis direction and the X-axis direction.Incidentally, in FIG. 28, the pitch of the gratings is illustratedlarger than the actual pitch for the sake of convenience. The same istrue also in other drawings.

Incidentally, also in this case, in order to protect the diffractiongrating, it is also effective to cover the grating, for example, with aglass plate with low thermal expansion that has water repellency, aspreviously described.

Incidentally, near the edge of the movable scales of each of the secondwater repellent plates 28 b′, a pattern for positioning (not shown)configured as is previously described for deciding the relative positionbetween an encoder head and a movable scale (to be described later) isarranged.

As shown in FIG. 28, on the −Y end surface and the −X end surface ofwafer table WTB′, a reflection surface 17 a and a reflection surface 17b are formed. As shown in FIG. 29, Y interferometer 16 and the three Xinterferometers 126 to 128 of interferometer system 118 (refer to FIG.32) irradiate interferometer beams (measurement beams) B4 ₁, B4 ₂, B5 ₁,B5 ₂, B6, and B7 and the like on reflection surfaces 17 a and 17 b,respectively. And Y interferometer 16 and the three X interferometers126 to 128 each receive the reflected lights, and measure the positionalinformation of wafer stage WST in the XY plane, and supply thepositional information which has been measured to main controller 20. Inthe second embodiment as well, in addition to the X, Y positions ofwafer table WTB′ (wafer stage WST), main controller 20 can also computerotation information (that is, pitching amount) in the θx direction,rotation information (that is, rolling amount) in the θy direction, androtation information (that is, yawing amount) in the θz direction, basedon the measurement results of Y interferometer 16 and X interferometers126 or 127.

Further, as shown in FIG. 27, movable mirror 41 having a concave-shapedreflection surface is attached to the side surface on the −Y side ofstage main section 91.

The pair of Z interferometers 43A and 43B configuring a part ofinterferometer system 118 irradiate two measurement beams B1 and B2 onfixed mirrors 47A and 47B via movable mirror 41, respectively, andmeasure the optical path length of measurement beams B1 and B2 byreceiving each of the reflected lights. And from the results, maincontroller 20 computes the position of wafer stage WST in four degreesof freedom (Y, Z, θy, and θz) directions.

In the second embodiment, position information within the XY plane(including the rotation information in the θz direction) of wafer stageWST (wafer table WTB′) is mainly measured by an encoder system (to bedescribed later) (refer to FIG. 32). Interferometer system 118 is usedwhen wafer stage WST is positioned outside the measurement area (forexample, near unloading position UP or loading position LP as shown inFIG. 30) of the encoder system. Further, interferometer system 118 isused secondarily such as when correcting (calibrating) a long-termfluctuation (for example, temporal deformation of the scale) of themeasurement results of the encoder system, or as backup at the time ofoutput abnormality in the encoder system. As a matter of course, theposition of wafer stage WST (wafer table WTB′) can be controlled usingboth interferometer system 118 and the encoder system together.

Incidentally, also in FIG. 32, the drive system of wafer stage WST andthe drive system of measurement stage MST are included and are shown asstage drive system 124.

In exposure apparatus 500 of the second embodiment, a primary alignmentsystem AL1 having a detection center at a position spaced apart fromoptical axis AX at a predetermined distance on the −Y side is placed onreference axis LV₀ shown in FIGS. 30 and 31. On one side and the otherside in the X-axis direction with primary alignment system AL1 inbetween, secondary alignment systems AL2 ₁ and AL2 ₂, and AL2 ₃ and AL2₄ whose detection centers are substantially symmetrically placed withrespect to reference axis LV₀ are severally arranged.

Next, the structure and the like of encoder system 150 (refer to FIG.32) which measures the positional information of wafer stage WST in theXY plane (including rotation information in the θz direction) will bedescribed.

In exposure apparatus 500, as shown in FIG. 30, a pair of head units62A′ and 62B′ is placed on the +X side and −X side of nozzle unit 32.These head units 62A′ and 62B′ are fixed to the mainframe (not shown)holding projection unit PU in a suspended state, via a support member.

As shown in FIG. 31, head units 62A′ and 62B′ are each equipped with aplurality of (in this case, four) two-dimensional heads (hereinaftershortly referred to as “heads” or “2D heads”) 165 ₂ to 165 ₅ and 164 ₁to 164 ₄ placed on reference axis LH at a distance WD, and heads 165 ₁and 164 ₅ placed at positions on the −Y side of nozzle unit 32 apredetermined distance away in the −Y direction from reference axis LH.Incidentally, the distance between heads 165 ₁ and 165 ₂ and heads 164 ₄and 164 ₅ in the X-axis direction is also set to WD. Hereinafter, heads165 ₁ to 165 ₅ and heads 164 ₁ to 164 will also be described as head 165and head 164, respectively, as necessary.

Head unit 62A′ constitutes a multiple-lens (five-lens, in this case) XYlinear encoder (hereinafter appropriately shortened to “XY encoder” or“encoder”) 170A (refer to FIG. 32) that measures the position of waferstage WST (wafer table WTB′) in the X-axis direction (the X-position)and the Y-axis direction (the Y-position) using moving scale 39Apreviously described. Similarly, head unit 62B′ constitutes amultiple-lens (five-lens, in this case) XY encoder 170B (refer to FIG.32) that measures the X-position and Y-position of wafer stage WST(wafer table WTB′) using moving scale 39B previously described. In thiscase, distance WD in the X-axis direction of the five heads 165 and 164(to be mare accurate, the irradiation points of the measurement beams(encoder beams) generated by heads 165 and 164 on the moving scales)that head units 62A′ and 62B′ are each equipped with, is set slightlynarrower than the width of moving scales 39A and 39B in the x-axisdirection. The term width of the moving scale, here, refers to the widthof the diffraction grating (or its formation area), or to be moreprecise, the range where position measurement using the head ispossible.

In the second embodiment, furthermore, as shown in FIG. 30, head units62C′ and 62D′ are respectively arranged a predetermined distance away onthe −Y side of head units 62B′ and 62A′. Head units 62C′ and 62D′ arefixed to the mainframe (not shown) holding projection unit PU in asuspended state, via a support member.

As shown in FIG. 31, head unit 62C′ is equipped with three heads 167 ₁to 167 ₃ placed on the −X side of the secondary alignment system AL2 ₁on reference axis LA at substantially the same distance as distance WD,and a head 167 ₄ placed on the +Y side of the secondary alignment systemAL2 ₁ a predetermined distance away in the +Y direction from referenceaxis LA. Incidentally, the distance between heads 167 ₃ and 167 ₄ in theX-axis direction is set slightly narrower than WD.

Head unit 62D′ is symmetrical to head unit 62C′ with respect toreference axis LV₀ previously described, and is equipped with four heads168 ₁ to 168 ₄ which are placed in symmetry to four Y heads 167 ₄ to 167₁ with respect to reference axis LV₀. Hereinafter, heads 167 ₁ to 167 ₄and heads 168 ₁ to 168 ₄ will also be described as head 167 and head168, as necessary.

On an alignment operation and the like, at least one head each of heads167 and 168 faces moving scales 39B and 39A, respectively. That is, ofthe measurement beams (encoder beams) that heads 167 and 168 emit, atleast one measurement beam each constantly irradiates moving scales 39Band 39A. The X position, Y position, and θz rotation of wafer stage WSTare measured by heads 167 and 168 (more specifically, XY encoders 170Cand 170D configured by heads 161 and 168)

Further, in the embodiment, at the time of baseline measurement and thelike of the secondary alignment system, heads 167 ₃ and 168 ₂ which areadjacent to the secondary alignment systems AL2 ₁ and AL2 ₄ in theX-axis direction face the pair of reference gratings 52 of FD bar 46,respectively, and by heads 167 ₃ and 168 ₂ that face the pair ofreference gratings 52, the Y position of FD bar 46 is measured at theposition of each reference grating 52. In the description below, theencoders configured by Y heads 167 ₃ and 168 ₂ which face the pair ofreference gratings 52, respectively, are referred to as Y linearencoders (also shortly referred to “Y encoders” or “encoders” as needed)170G and 170H (refer to FIG. 32) Incidentally, Y encoders 170G and 170Hare described as such, focusing on the point that heads 167 ₃ and 168 ₂which configure a part of encoders 170C and 170D function not as 2Dheads, but as Y heads by facing the pair of reference gratings 52. Inthe following description as well, Y encoders 170G and 170H are to existbesides XY encoders 170C and 170D, for the sake of convenience.

Each of the encoders described above supply their measurement values tomain controller 20. Main controller 20 controls the position (includingrotation (yawing) in the θz direction) within the XY plane of wafertable WTB based on the measurement values of XY encoders 170A and 170Bor 170C and 170D, and also controls the rotation of FD bar 46(measurement stage MST) in the θz direction, based on the measurementvalues of Y encoders 170G and 170H.

FIG. 32 shows the main configuration of the control system of exposureapparatus 500. The control system is mainly configured of maincontroller 20 composed of a microcomputer (or workstation) that performsoverall control of the entire apparatus.

In exposure apparatus 500 of the second embodiment, because theplacement of the moving scales on wafer table WTB′ previously describedand the placement of the heads previously described were employed, asshown in FIG. 33, in the effective stroke range of wafer stage WST (morespecifically, the range where the stage moves for alignment and exposureoperation), heads 165 and 164 (head units 62A′ and 62B′) or heads 168and 167 (head units 62D′ and 62C′) face moving scales 39A and 39B,respectively, without fail. Incidentally, in FIG. 33, the heads facingthe corresponding moving scale and are used for position measurement areshown circled by a solid line.

To enter the details furthermore, during the exposure operation by thestep-and-scan method in which a pattern of reticle R is transferred ontowafer W, main controller 20 uses the measurement values of heads 165 and164, which are one head each facing removing scales 39A and 39B,respectively, out of the five heads each that heads 165 and 164 of headunits 62A′ and 62B′ have, to control the position and rotation (rotationin the θz direction) of wafer stage WST within the XY plane.

Further, on the wafer alignment, main controller 20 uses the measurementvalues of heads 168 and 167 (encoders 170D and 170C) of head units 62D′and 62C′ each facing moving scales 39A and 39B to control the positionand rotation (rotation in the θz direction) of wafer stage WST withinthe XY plane.

Further, when main controller 20 drives wafer stage WST in the X-axisdirection as shown by an outlined arrow in FIG. 33, heads 165 and 164,which measure the X position and Y position of wafer stage WST, aresequentially switched to adjacent heads 165 and 164 as shown by an arrowe₁ in FIG. 33. For example, the head is switched from head 164 ₂surrounded by the circle in a solid line to head 164 ₃ surrounded by thecircle in a dotted line (and from head 165 ₂ surrounded by the circle ina solid line to head 165 ₃ surrounded by the circle in a dotted line).More specifically, in the second embodiment, in order to perform theswitching (linkage) of the heads 165 and 164 smoothly, distance WDbetween the adjacent heads of heads 165 and 164 that head units 62A′ and62C′ are equipped with, is set smaller than the width of moving scales39A and 39B in the X-axis direction as is previously described.

Next, details on a configuration and the like of encoder systems 170A to170D will be described, taking up encoder 170B shown enlarged in FIG. 34representatively as an example. FIG. 34 shows one of the 2D heads 164 ofhead unit 62B′ that irradiates a detection beam (a measurement beam) onmoving scale 39B.

As shown in FIG. 34, head 164 includes a light source 164 a whichirradiates a laser beam on moving scale (movable grating) 39B arrangedat the end on the −X side on the upper surface of wafer table WTB′,fixed scales 164 b ₁ and 164 b ₂, and 164 b ₃ and 164 b ₄ that have afixed positional relation with light source 164 a and condensediffraction lights generated at moving scale 39B, an index scale 164 cwhich makes diffraction lights condensed at fixed scales 164 b ₁ and 164b ₂ and fixed scale 164 b ₃ and 164 b ₄ interfere, respectively, and adetector 164 d, which detects the lights interfering at index scale 164c. Further, the posture of light source 164 a is set from the viewpointof design so that the optical axis of the laser beam emitted from lightsource 164 a becomes perpendicular to the XY plane.

Fixed scales 164 b ₁ and 164 b ₂ are transmission-type phase gratingsconsisting of plates on which diffraction gratings having a periodicdirection in the Y-axis direction have been formed. Meanwhile, fixedscales 164 b ₃ and 164 b ₄ are transmission-type phase gratingsconsisting of plates on which diffraction gratings having a periodicdirection in the X-axis direction have been formed. Index scale 164 c istransmission-type two-dimensional grating on which a diffraction gratinghaving a periodic direction in the Y-axis direction and a diffractiongrating having a periodic direction in the X-axis direction have beenformed. Further, detector 164 d, for example, includes a quartereddetector or a CCD.

Fixed scale 164 b ₁ diffracts the −1st order diffraction light which hasbeen generated in the diffraction grating of moving scale 39B whoseperiodic direction is in the Y-axis direction and generates the +1storder diffraction light, which proceeds toward index scale 164 c.Further, fixed scale 164 b ₂ diffracts the +1st order diffraction lightwhich has been generated in the diffraction grating of moving scale 395whose periodic direction is in the Y-axis direction and generates the−1st order diffraction light, which proceeds toward index scale 164 c.

In this case, the +1st order diffraction light and the −1st orderdiffraction light generated at fixed scale 164 b ₁ and fixed scale 164 b₂ overlap each other at the same position on index scale 164 c. Morespecifically, +1st order diffraction light and the −1st orderdiffraction light interfere on index scale 164 c.

Meanwhile, fixed scale 164 b ₃ diffracts the −1st order diffractionlight which has been generated in the diffraction grating of movingscale 39 whose periodic direction is in the X-axis direction andgenerates the −1st order diffraction light, which proceeds toward indexscale 164 c. Further, fixed scale 164 b ₄ diffracts the +1st orderdiffraction light which has been generated in the diffraction grating ofmoving scale 395 whose periodic direction is in the X-axis direction andgenerates the −1st order diffraction light, which proceeds toward indexscale 164 c.

In this case, the +1st order diffraction light and the −1st orderdiffraction light generated at fixed scale 164 b ₃ and fixed scale 164 b₄ overlap each other at the same position on index scale 164 c. Morespecifically, +1st order diffraction light and the −1st orderdiffraction light interfere on index scale 164 c.

In this case, the diffraction angle of the diffraction lights generatedin each grating of the moving scales is decided, based on the wavelengthof the laser beam emitted from light source 164 a and the pitch ofmoving scale (movable grating) 39B, and further, by appropriatelydeciding the wavelength of the laser beam and the pitch of fixed scales164 b ₁ to 164 b ₄, the apparent bending angle of the +−1st orderdiffraction light generated in the moving scale (movable grating) 39B isdecided.

In this case, in head 164 (encoder 170B), a two-dimensional pattern(checkered pattern) appears on detector 164 d. Because thetwo-dimensional pattern changes according to the position of wafer stageWST i n the Y-axis direction and the X-axis direction, by measuring thischange with the quartered device configuring at least a part of detector164 d. or the CCD and the like, the position of wafer stage WST in theY-axis direction and the X-axis direction can be measured.

Incidentally, a moire fringe can be generated by rotating index scale164 c around the Z-axis by a minutely small amount, and the moirefringes can be used to measure wafer stage WST.

As is obvious from the description above, because the optical pathlength of the two beams which are made to interfere is extremely shortand also are almost equal to each other in encoder 170B different fromeach of the interferometers of interferometer system 118, the influenceby air fluctuations can mostly be ignored. Other encoders 170A, 170C,and 170D are also configured similar to encoder 170B. As each encoder,an encoder having a resolution of, for example, around 0.1 nm is used.

In exposure apparatus 500 of the second embodiment, in the case ofexposure operation described below, main controller 20 controls theposition (including rotation in the θz direction) of wafer stage WST(wafer table WTB′) in the XY plane, based on measurement values of twoencoders 170A and 170B configured by two heads 165 and 164 that facemoving scales 39A and 39B, respectively, and various correctioninformation (the correction information includes stage position inducederror correction information of each encoder according to the positionalinformation (including tilt information) of wafer stage WST related to adirection besides the measurement direction of the encoder measured byinterferometer system 118, characteristics information of the movingscale (for example, the degree of flatness of the grating surface,and/or the grating formation error and the like), and Abbe offsetquantity (Abbe error correction information) of the moving scale and thelike).

Stage position induced error correction information, here, refers to thedegree to which the position (pitching amount, rolling amount, yawingamount and the Z position and the like) of wafer stage WST in adirection besides the measurement direction (in the second embodiment,directions besides the X-axis direction and the Y-axis direction, suchas, for example, the ex direction, the θy direction, the θz directionand the Z-axis direction) with respect to the encoder head affects themeasurement values of the encoder. Incidentally, in a brief outline, thestage position induced error correction information is acquiredbeforehand in the following manner.

More specifically, main controller 20 changes wafer stage WST into aplurality of different postures, and for each posture, moves wafer stageWST in the Z-axis direction at a predetermined stroke range whileirradiating a detection light on specific areas of moving scales 39A and39B from heads 165 and 164 in a state where the posture of wafer stageWST is maintained based on the measurement results of interferometersystem 118, and during the movement, performs sampling of themeasurement results of the encoder. In this manner, variationinformation (error characteristics curve) of the measurement values ofthe encoder according to the position in a direction (the Z-axisdirection) orthogonal to the movement plane of wafer stage WST for eachposture can be obtained. Then, by performing a predetermined operationbased on the sampling results, or in other words, the variationinformation of the measurement values of the encoder according to theposition of wafer stage WST in the Z-axis direction for each posture,main controller 20 obtains the correction information of the measurementvalues of the encoder according to the positional information of waferstage WST in the direction besides the measurement direction.Accordingly, the stage position induced error correction informationused to correct the measurement errors of the encoder due to relativechange between a head and a moving scale in the direction besides themeasurement direction can be decided by a simple method.

Further, in the second embodiment, in the case of deciding thecorrection information described above for a plurality of headsconfiguring the same head unit, such as for example, a plurality ofheads 164 configuring head unit 62B, because the correction informationof each head 164 (each encoder) facing moving scale 39B is decided basedon sampling results when detection lights are irradiated from each head164 on the same specific area of the corresponding scale 39B and thesampling of the measurement results of the encoder described above isperformed, as a consequence, geometric errors caused by the gradient ofthe head are also corrected by using this correction information. Inother words, on obtaining the correction information of a plurality ofencoders serving as an object: corresponding to the same moving scale,main controller 20 obtains the correction information of the encoderstaking into consideration the geometric errors caused by the gradient ofheads of the object encoders which occur when moving wafer stage WST inthe Z-axis direction. Accordingly, in the second embodiment, cosineerrors which occur due to different gradient angles of the plurality ofheads also do not occur. Further, even if a gradient does not occur inhead 164, when, for example, a measurement error occurs in the encoderdue to the optical properties (such as telecentricity) of the head,generation of measurement errors, or in turn, a decrease in positioncontrol accuracy of wafer stage WST, can be prevented by obtaining bythe correction information in a similar manner. More specifically, inthe second embodiment, wafer stage WST is driven so as to compensate forthe measurement errors (hereinafter also referred to as a head inducederror) of the encoder system caused by a head unit. Incidentally, forexample, the correction information of the measurement values of theencoder system can be computed, based on characteristics information(including for example, the gradient of the head and/or the opticalproperties and the like) of the head unit.

Further, characteristics information of the moving scale is informationon the unevenness (including the tilt) of the surface (to be precise, inthe case the diffraction grating surface and the diffraction grating arecovered with a cover glass, including the surface of the cover glass) ofthe scale, and/or the grating formation error (warp of the grating pitchand/or the grid line) and the like, and is measured in advance.

Further, the Abbe offset quantity refers to a difference between theheight (the Z position) of the surface (the diffraction grating surface)of each moving scale on wafer table WTB′ and the height of a referencesurface which includes the exposure center (the center of exposure areaIA previously described, and in the second embodiment, coincides withoptical axis AX of projection optical system PL). When there is an error(or a gap) in the height of the reference surface of wafer stage WST andthe height of the surface (the diffraction grating surface) of eachmoving scale, the so-called Abbe error occurs in the measurement valuesof the encoder on rotation (pitching or rolling) around an axis (theX-axis or the Y-axis) parallel to the XY plane of wafer stage WST. Thereference surface, in this case, is the surface which becomes areference of displacement in the Z-axis direction of wafer stage WSTmeasured by interferometer system 118, and refers to a surface (in thesecond embodiment, coincides with the image plane of projection opticalsystem PL) which becomes a reference of alignment (position control) ofeach shot area on wafer W in the Z-axis direction. Incidentally, in abrief outline, the Abbe offset quantity is acquired beforehand in thefollowing manner.

More specifically, prior to a start of the lot process in which waferstage WST is driven, at the time such as, for example, the startup ofthe apparatus, a calibration process to acquire the Abbe offset quantityof each moving scale (diffraction grating) surface previously describedis performed as one of a series of calibration of the encoder systemwhich measures the positional information of wafer stage WST within theXY plane. More specifically, main controller 20 inclines wafer stage WSTwith respect to the XY plane at an angle α in the periodic direction ofthe diffraction grating, based on measurement values of interferometersystem 118 which measures the tilt angle of wafer stage WST with respectto the XY plane in the periodic direction of the diffraction grating foreach moving scale of the encoder system, and computes the Abbe offsetquantity of the diffraction grating surface, based on the measurementvalues of the encoder system before and after the inclination andinformation on angle a measured with interferometer system 118. Then,main controller 20 stores the information that has been computed inmemory.

Next, a parallel processing operation that uses wafer stage WST andmeasurement stage MST in exposure apparatus 500 of the second embodimentwill be described, based on FIGS. 35 to 39. Incidentally, during theoperation below, main controller 20 performs the open/close control ofeach valve of liquid supply unit 5 of local liquid immersion unit 8 andliquid recovery unit 6 in the manner previously described, and water isconstantly filled directly under tip lens 191 of projection opticalsystem PL. However, in the description below, for the sake ofsimplicity, the explanation related to the control of liquid supply unit5 and liquid recovery unit will be omitted. Further, many drawings areused in the operation description hereinafter, however, reference codesmay or may not be given to the same member for each drawing. Morespecifically, the reference codes written are different for eachdrawing, however, such members have the same configuration, regardlessof the indication of the reference codes. The same can be said for eachdrawing used in the description so far.

FIG. 35 shows a state in which an exposure the step-and-scan method ofwafer W mounted on wafer stage WST is performed. This exposure isperformed by repeating a movement between shots in which wafer stage WSTis moved to a scanning starting position (acceleration, staringposition) to expose each shot area on wafer W and scanning exposure inwhich the pattern formed on reticle R is transferred onto each shot areaby the scanning exposure method, based on results of wafer alignment(for example, EGA) and the like which has been performed prior to thebeginning of exposure. Further, exposure is performed in the followingorder, from the shot area located on the −Y side on water W to the shotarea located on the +Y side.

During the exposure operation described above, main controller 20controls the position (including the rotation in the θz direction) ofwafer stage WST (wafer table WTB′) within the XY plane, based on themeasurement values of the two encoders 170A and 170B configured by twoheads 165 and 164 that face moving scales 39A and 39B, respectively, andvarious correction information (stage position induced error correctioninformation, characteristics information of the moving scales, and Abbeerror correction information and the like) previously described tocorrect the encoder measurement values. Further, during the exposureoperation described above, main controller 20 controls the θy rotation(rolling) and the θx rotation (pitching) of wafer stage WST based onmeasurement values of X interferometer 126 (or Z interferometers 43A and43B) and Y interferometer 16. Incidentally, at least one of the position(Z position) of wafer stage WST in the Z-axis direction, the θy rotation(rolling), and the θx rotation (pitching), such as, for example, the Zposition and the θy rotation can be measured by other sensors, such asfor example, a sensor which detects the Z position of the upper surfaceof wafer table WTB′, such as, for example, a head of an opticaldisplacement sensor similar to an optical pickup used in a CD drivedevice. In any case, main controller 20 controls (focus leveling controlof wafer W) the position of the Z-axis direction, the θy rotation, andthe θx rotation of wafer stage WST (wafer table WTB′) during theexposure, based on the measurement results of the surface positioninformation of the wafer measured by main controller 20 beforehand andthe measurement results of encoder system 150 and/or interferometersystem 118.

When wafer stage WST moves in the X-axis direction during the exposureoperation by the step-and-scan method described above, the switching ofthe head previously described is performed along with the movement. Inthis manner, main controller 20 performs stage control by appropriatelyswitching the encoder to use depending on the position coordinate ofwafer stage WST.

Incidentally, independent from the position measurement of wafer stageWST described above using the encoder system, position (X, Y, Z, θx, θy,θz) measurement of wafer stage WST using interferometer system 118 isconstantly performed. For example, of X interferometers 126, 127, and128, one interferometer is used according to the Y position of waferstage WST. For example, X interferometer 126 is used secondarily duringthe exposure, as shown in FIG. 126.

When exposure of wafer W has been completed, main controller 20 driveswafer stage WST toward unload position UP. On this drive, wafer stageWST and measurement stage MST which were apart during exposure come intocontact or move close to each other with a clearance of, for example,around 300 μm in between, and shift to a scrum state. In this case, theend surface on the −Y side of FD bar 46 on measurement table MTB and theend surface on the +Y side of wafer table WTB come into contact or moveclose together. And by moving both stages WST and MST in the −Ydirection while maintaining the scrum condition, liquid immersion area14 formed under projection unit PU moves to an area above measurementstage MST.

After shifting to the scrum state described above, when wafer stage WSTmoves further to the −Y direction and moves off from the effectivestroke area (the area in which wafer stage WST moves at the time ofexposure and wafer alignment), all the heads that constitute encodersystem 150 move off from the corresponding scales on wafer table WTB′.Therefore, stage control based on the measurement results of encodersystem 150 is no longer possible. Just before this, main controller 20switches the stage control to a control based on the measurement resultsof interferometer system 118. In this case, of the three Xinterferometers 126, 127, and 128, X interferometer 128 is used.

Then, as shown in FIG. 36, wafer stage WST releases the scrum state withmeasurement stage MST, and then moves to unload position UP. After themovement, main controller 20 unloads wafer W on wafer table WTB′. Andthen, as shown in FIG. 37, wafer stage WST is driven in the +X directionto loading position LP, and the next wafer W is loaded on wafer tableWTB′.

In parallel with these operations, main controller 20 performs Sec-BCHK(a secondary base line check) in which position adjustment of FD bar 46supported by measurement stage MST in the XY plane and baselinemeasurement of the four secondary alignment system AL2 ₁ to AL2 ₄ areperformed. In this case, Y encoders 170G and 170H previously describedare used to measure the rotation information of FD bar 46 in the θzdirection.

Next, main controller 20 drives wafer stage WST, and as shown in FIG.38, positions reference mark FM on measurement plate 30 within adetection field of primary alignment system AL1, and performs the formerprocess of Pri-BCHK in which the reference position is decided forbaseline measurement of alignment system AL1, and AL2 ₁ to AL2 ₄.

When the processing is performed, as shown in FIG. 38, two heads 168 ₃and 167 ₂ (shown circled in the drawing) move to face moving scales 39Aand 39B, respectively. Then, main controller 20 switches the stagecontrol from a control using interferometer system 118, to a controlusing encoder system 150 (encoders 170D and 170C). Interferometer system118 is used secondarily again. Incidentally, of the three Xinterferometers 126, 127, and 128, X interferometer 127 is used.

Then, main controller 20 performs wafer alignment (EGA), using primaryalignment system AL1 and secondary alignment systems AL2 ₁ to AL2 ₄(refer to the star mark in FIG. 39).

Incidentally, in the second embodiment, wafer stage WST and measurementstage MST are to be shifted to the scrum state by the time waferalignment shown in FIG. 39 begins. Main controller 20 drives both stagesWST and MST in the +Y direction, while maintaining the serum state.Then, the water of liquid immersion area 14 is moved from abovemeasurement table MTB to an area on wafer table WTB′.

In parallel with wafer alignment (EGA), main controller 20 performs thelatter processing of Pri-BCHK in which the intensity distribution of aprojection image of a mark on reticle with respect to the XY position ofwafer table WTB′ is measured using aerial image measuring device 45.

When the operation described above has been completed, main controller20 releases the scrum state of both stages WST and MST. And, as shown inFIG. 35, exposure by the step-and-scan method is performed, and areticle pattern is transferred on to a new wafer W. Hereinafter, asimilar operation is executed repeatedly.

As described above, according to exposure apparatus 500 related to thesecond embodiment, a pair of moving scales 39A and 39B having atwo-dimensional grating is arranged on both ends in the X-axis directionon the upper surface of wafer stage WST, and a pair of head units 62A′and 62B′ having at least one head 165 or 164, which can constantly facemoving scale 39A and 39B when wafer stage WST is located in the movementrange to perform the exposure operation, is arranged on both sides ofprojection unit PU (nozzle unit 32) in the X-axis direction. By thisarrangement, main controller 20 can measure the positional information(including rotation information in the θz direction) of wafer stage WSTwithin the XY plane during the exposure operation by the step-and-scanmethod with high precision, using heads 165 and 164, or morespecifically encoders 170A and 170B. Accordingly, with the secondembodiment, the layout of the encoder head is simple when compared withthe exposure apparatus disclosed as an embodiment in the pamphlet ofInternational Publication No. 2007/097379.

Further, because the scale does not have to be placed in the area at theend on the +Y side on the upper surface of wafer table WTB′ in thesecond embodiment, or more specifically, at the area where liquidimmersion area 14 passes through frequently, even if the liquid remainsor dust and the like adheres in that area, there is no risk of themeasurement accuracy of the encoder system deteriorating.

Further, according to exposure apparatus 500 related to the secondembodiment, each of the five heads 165 ₁ to 165 ₅ and 164 ₁ to 164 ₅belonging to head units 62A′ and 62B′ respectively, that face movingscales 39A and 39B on exposure and are used for position measurement ofwafer stage WST in the X-axis direction, the Y-axis direction, and theθz direction, are placed so that as for the X-axis direction, distanceWD between adjacent heads is set to a desired distance as in, forexample, 70 mm, which takes into consideration the width of movingscales 39A and 39B in the X-axis direction (for example, 76 mm), and theY position of heads 165 ₁ and 164 ₅ located closest to the center ofprojection unit PU are also placed differently from the other (remainingfour) heads, according to an open space (in the second embodiment, theopen space around nozzle unit 32). Accordingly, placement of each of thefive heads 165 and 164 of head units 62A′ and 62B′ according to the openspace becomes possible, as well as reducing the size of the overallapparatus by improving the space efficiency. In addition to this,linkage (switching of the heads to be used) between each of the fiveheads of heads 165 and 164 of head units 62A′ and 62B′ can be performedwithout any trouble. Accordingly, by encoder system 150 including XYencoders 170A and 170B that have head units 62A′ and 62B′, respectively,the position of wafer stage WST in the XY plane can be measured withhigh precision upon exposure, without being affected by air fluctuation.

Further, according to exposure apparatus 500 related to the secondembodiment, when main controller 20 drives wafer stage WST on exposureand the like, main controller 20 controls the position (includingrotation in the θz direction) of wafer stage WST within the XY planewith high precision, based on the measurement values of encoder system150 (encoders 170A and 170B) and correction information (at least one ofthe stage position induced error correction information (including thecorrection information of head induced error), characteristicsinformation of the moving scale, and Abbe error correction information)used to correct the measurement values of each encoder.

Further, according to exposure apparatus 500 related to the secondembodiment, by repeating a movement operation between shots in whichwafer stage WST is moved to a scanning starting position (accelerationstarting position) for exposure of each shot area on wafer W and ascanning exposure operation in which a pattern formed on reticle R istransferred onto each shot area by a scanning exposure method, based onthe latest baseline obtained from the baseline measurement of thealignment system previously described which is performed each time onwafer exchange and the results of wafer alignment EGA), it becomespossible to transfer the pattern of reticle R on the plurality of shotareas on wafer W with good precision (overlay accuracy). Furthermore, inthe second embodiment, because a high-resolution exposure can berealized by liquid immersion exposure, a fine pattern can be transferredwith good precision on wafer W also from this viewpoint.

Furthermore, with exposure apparatus 500 related to the secondembodiment, periphery edge exposure unit 51 and multipoint AF system (90a, 90 b) are actually arranged at positions similar to the firstembodiment previously described. Therefore, according to exposureapparatus 500, by wafer stage WST (wafer W) linearly passing theplurality of detection points (detection area AF) of the multipoint AFsystem (90 a, 90 b), the detection area of the plurality of alignmentsystems AL1, and AL2 ₁ to AL2 ₄, and below periphery edge exposure unit51, three operations which are detection of surface position informationof substantially the entire surface of wafer W, detection of all thealignment marks (for example, alignment marks in the alignment area onEGA) which should be detected on wafer W, and periphery edge exposure ofwafer W are completed, as in exposure apparatus 100 of the firstembodiment. Therefore, throughput can be improved remarkably whencompared with the case when detection operation of the alignment marks,detection operation of the surface position information (focusinformation), and periphery edge exposure operation are performedindependently (separately).

Further, in exposure apparatus 500 related to the second embodiment, asurface position measurement system similar to the one described in thefirst embodiment can be arranged. Accordingly, it becomes possible toperform focus mapping and surface position control of wafer W using theresults of the focus mapping similar to the first embodiment.Accordingly, in the embodiment, although the working distance betweentip lens 191 and wafer W surface is narrow, focus leveling control ofwafer W on exposure can be performed with good precision, without anytrouble.

Further, in the second embodiment described above, the case has beendescribed where exposure apparatus 500 is equipped with an encodersystem which is configured of moving scales 39A and 39B (scale members)placed on wafer stage WST, and facing the scales, head units 62A′ to62D′ placed external to wafer stage WST, or more specifically, below themainframe (not shown) holding projection unit PU. However, as well asthis, the encoder heads can be arranged on wafer stage WST, and thescale members can be arranged external to wafer stage WST as in thefollowing third embodiment.

A Third Embodiment

FIG. 40 is a planar view that shows a stage device equipped in anexposure apparatus of a third embodiment and a placement of a sensorunit. The exposure apparatus of the third embodiment is different onlyin the configuration of the encoder system when compared with theexposure apparatus of the second embodiment previously described, andthe configuration is the same for other sections. Accordingly, thedescription below will be focusing mainly on the difference, which isthe encoder system. Further, the same reference numerals will be usedfor the same or similar sections as in the second embodiment previouslydescribed, and a description thereabout will be omitted.

As shown in FIG. 40, in the third embodiment, 2D heads 172 ₁ to 172 ₆and 174 ₁ to 174 ₆ are arranged, respectively, on the pair of secondwater repellent plates 28 b′ on the upper surface of wafer table WTB′instead of moving scales 39A and 39B, in a direction parallel toreflection surface 17 b at a predetermined distance WD. As each of the2D heads 172 ₁ to 172 ₆ and 174 ₁ to 174 ₆, a head having aconfiguration similar to 2D heads 164,165,167, and 168 previouslydescribed is used. 2D heads 172 ₁ to 172 ₆ and 2D heads 174 ₁ to 174 ₆are placed symmetric to the center line of wafer table WTB′.Hereinafter, 2D heads 172 ₁ to 172 ₆ and 2D heads 174 ₁ to 174 ₆ willalso be described, appropriately, as heads 172 and 174, respectively.

Meanwhile, on the +X side and the −X side of nozzle unit 32, a pair offixed scales 39A′ and 39B′ are placed, respectively, with the X-axisdirection serving as a longitudinal direction. Fixed scales 39A′ and39B′ are shaped, each having a rectangular shaped cutout portion formedin a part of one side on one end in the longitudinal direction of arectangle, as shown in FIG. 40, and an extended portion having the sameshape as the cutout portion arranged on the other side of the one end.In this case, fixed scale 39A′ is placed in a state substantially incontact with the surface of nozzle unit 32 on the +X side with theX-axis direction serving as the longitudinal direction, and is shapedhaving a rectangular cutout portion is formed at a part of the −X end ofthe nozzle unit on the +Y side, and an extended portion having the sameshape as the cutout portion arranged at the −X end on the −Y side. Theextended portion protrudes slightly more to the −Y side than nozzle unit32. Fixed scale 39B′ has a shape symmetric to fixed scale 39A′, and isplaced symmetrically with respect to a reference line LV₀. Fixed scales39A′ and 39B′ are fixed to the rear surface of the mainframe (not shown)holding projection unit PU, parallel to the XY plane. The length offixed scales 39A′ and 39B′ are slightly shorter when compared withmoving scales 39A and 39B previously described, and on the lowersurfaces (the surface on the −Z side) of the scales, the reflection typetwo-dimensional diffraction gratings previously described are formed.

In the third embodiment, furthermore, as shown in FIG. 40, on the −Yside of fixed scales 39A′ and 39B′ a predetermined distance (forexample, substantially the same dimension as the width of fixed scale39A′) away, fixed scales 39D′ and 39C′ having rectangular shapes areplaced, with the X-axis direction serving as the longitudinal direction.Fixed scales 39D′ and 39C′ are placed symmetrically with respect toreference line LV ₀ previously described. Further, fixed scales 39D′ and39C′ are placed in proximity to secondary alignment systems AL2 ₄ andAL2 ₁, respectively. Fixed scales 39D′ and 39C′ are fixed to the rearsurface of the mainframe (not shown) holding projection unit PU,parallel to the XY plane. The length of fixed scales 39D′ and 39C′ areslightly shorter when compared with fixed scales 39A′ and 39B′previously described, and on the lower surfaces (the surface on the −Zside) of the scales, the reflection type two-dimensional diffractiongratings previously described are formed.

Further, on the upper surface of FD bar 46, instead of the pair ofreference gratings 52, a pair of 2D heads 176 is arranged.

2D heads 172 ₁ to 172 ₆ constitute a multiple-lens (six-lens, in thiscase) XY encoder 170A′ (refer to FIG. 41) that measures the X positionand the Y position of water stage WST (wafer table WTB′) using fixedscale 39A′ or 39D′ previously described. Similarly, 2D heads 174 ₁ to174 ₆ constitute a multiple-lens (five-lens, in this case) XY encoder170B′ (refer to FIG. 41) that measures the X position and the Y positionof wafer stage WST (wafer table WTB′) using fixed scale 39B′ or 39C′previously described.

On exposure operation and the like, at least one each of heads 172 and174 face fixed scales 39A′ and 39B′, respectively. That is, of themeasurement beams (encoder beam) that heads 172 and 174 emit, at leastone measurement beam each constantly irradiates fixed scales 39A′ and39B′. The X position, Y position, and θz rotation of wafer stage WST aremeasured by heads 172 and 174 (more specifically, encoders 170A′ and170B′ configured by heads 172 and 174).

Further, on alignment operation and the like, at least one each of heads174 and 172 face fixed scales 39C′ and 39D′, respectively. That is, ofthe measurement beams (encoder beams) that heads 174 and 172 emit, atleast one measurement beam each constantly irradiates moving scales 39C′and 39D′. The X position, Y position, and θz rotation of wafer stage WSTare measured by heads 174 and 172 (more specifically, encoders 170B′ and170A′ configured by heads 174 and 172).

Further, in the third embodiment, at the time of base line measurementand the like of the secondary alignment system, the pair of 2D heads 176on FD bar 46 faces fixed scales 39C′ and 39D′, and the X and Y positionsand the θz rotation of FD bar 46 is measured by the pair of 2D heads176. In the description below, the encoders configured by the pair of 2Dheads 176 which face fixed scales 39C′ and 39D′, respectively, arereferred to as encoders 170C′ and 170D′ (refer to FIG. 41).

The four encoders 170A′ to 170D′ described above supply theirmeasurement values to main controller 20. Main controller 20 controlsthe position (including rotation (yawing) in the θz direction) withinthe XY plane of wafer table WTB′ based on the measurement values ofencoders 170A′ and 170B′, and also controls the position of FD bar 46 inthe X, Y, and θz direction, based on the measurement values of encoders170C′ and 170D′.

The configuration for other sections is the same as the secondembodiment previously described.

According to the exposure apparatus of the third embodiment configuredin the manner described above, main controller 20 performs the controloperation of each section in a similar manner as exposure apparatus 500or the second embodiment previously described, which makes at possibleto obtain an effect equivalent to the first embodiment.

Incidentally, in the second and third embodiments described above, whilea 2D head having the configuration shown in FIG. 34 is used as anexample as an encoder head, as well as this, two one-dimensional headscan be combined to configure a two-dimensional head. More specifically,the two-dimensional head referred to in the description includes a headwhich is a combination of two one-dimensional heads.

In the first to third embodiment described above, while the case hasbeen described where the present invention has been applied to anexposure apparatus which is equipped with a wafer stage and ameasurement stage, as well as this, the present invention can also beapplied to an exposure apparatus equipped with only a single stage, or amulti-stage type exposure apparatus equipped with a plurality of waferstages, such as for example, a twin-stage type exposure apparatus, as isdisclosed in, for example, U.S. Pat. Nos. 6,590,634, 5,969,441,6,208,407 and the like. In this case, in parallel with the exposurewhich is performed on the wafer held by one of the two wafer stages, thecontroller of the exposure apparatus can control the periphery edgeexposure unit which is placed on the movement path between the area (ameasurement station) where measurement such as alignment measurement ofthe wafer is performed and the area (an exposure station) where exposureof the wafer is performed, while moving the other wafer stage in atleast the Y-axis direction, and can perform the periphery edge exposureof a part of the shot areas in the periphery portion of the wafer heldby the other wafer stage while the stage passes under the periphery edgeexposure unit while moving toward the exposure position.

Further, the periphery edge exposure operation can be started during themeasurement operation at the measurement station. In this case, theperiphery edge exposure operation is to be completed after finishing themeasurement operation and also before starting the exposure.

Incidentally, the periphery edge exposure unit can be placed at themeasurement station along with the alignment systems (AL1, AL2 ₁ to AL2₅), and the periphery edge exposure operation can be performed duringthe measurement operation.

Further, while the position control (including the period, while atleast a part of the periphery edge exposure operation is beingperformed) of the wafer stage between the measurement station and theexposure station can be performed using any kind of a measurementdevice, it is preferable to perform the control, using the encodersystem or the interferometer system described above.

Further, in the twin stage type exposure apparatus, the periphery edgeexposure operation can be performed in the proceeding path (morespecifically, the movement path of the wafer stages from the measurementstation to the exposure station), or the operation can be performed inthe returning path (more specifically, the movement path of the waferstage from the exposure station to the measurement station (unloadingposition)), or, the periphery edge exposure operation of one wafer canbe performed dividing the operation into the proceeding path and thereturning path.

Incidentally, in the case of applying the second and third embodimentsto the twin stage type exposure apparatus, the periphery edge exposureunit does not have to be arranged, and only the encoder system havingthe 2D heads (2D encoders) previously described has to be adopted as theposition measurement device of at least one wafer stage. Morespecifically, in the second and third embodiments described above, whilethe encoder system having the 2D heads previously described is required,the configuration besides the encoder system, the sequence (stagemovement and a measurement operation are performed in parallel) and thelike can be combined and employed optionally and is not essential.

Further, in the second and third embodiments above, while the case hasbeen described where measurement system 200 includes both interferometersystem 118 and encoder system 150, as well as this, the measurementsystem can include only one of interferometer system 118 and encodersystem 150.

Next, a fourth embodiments of the present invention related to a twinstage type exposure apparatus will be described.

A Fourth Embodiment

Hereinafter, a fourth embodiment of the present invention will bedescribed, with reference to FIGS. 42 to 76. Here, the same referencenumerals will be used for the same or similar sections as in the firstembodiment, and/or the second embodiment previously described, and adetailed description thereabout will be simplified or omitted.

FIG. 42 schematically shows a configuration of an exposure apparatus1000 in the fourth embodiment. Exposure apparatus 1000 is a projectionexposure apparatus by the step-and-scan method, or a so-called scanner.As it will be described later, because a projection optical system PL isarranged also in the fourth embodiment, in the description below, adirection parallel to an optical axis AX of projection optical system PLwill be described as the Z-axis direction, a direction within a planeorthogonal to the Z-axis direction in which a reticle and a wafer arerelatively scanned will be described as the Y-axis direction, adirection orthogonal to the Z-axis and the Y-axis will be described asthe X-axis direction, and rotational (inclination) directions around theX-axis, the Y-axis, and the Z-axis will be described as θx, θy, and θzdirections, respectively.

Exposure apparatus 1000 is equipped with an illumination system 10, areticle stage RST which holds a reticle R illuminated by illuminationlight IL from illumination system 10, a projection unit PU includingprojection optical system PL which irradiates illumination light ILoutgoing from reticle R on a wafer, a stage device 1050 including twowafer stages WST1 and WST2, a local liquid immersion device 8 and acontrol system of these sections. On wafer stages WST1 and WST2, wafersW1 and W2 are held, respectively.

Stage device 1050, as shown in FIG. 42, is equipped with two waferstages WST1 and WST2 placed above a base board 12, a measurement system200 (refer to FIG. 47) that measures positional information of waferstages WST1 and WST2, and a stage drive system 124 (refer to FIG. 47)which drives wafer stages WST1 and WST2 and the like. Measurement system200 includes an interferometer system 118, an encoder system 150, and asurface position measurement system 180 as shown in FIG. 47.

Wafer stages WST1 and WST2 are supported by levitation above base board12 via a clearance of several μm by, for example, air sliders (to bedescribed later) that each stage has. And, by a planar motor describedbelow configuring stage drive system 124, wafer stages WST1 and WST2 aredrivable independently within the XY plane along the upper surface(movement guide surface) of base board 12.

Wafer stage WST1, as shown in FIGS. 42 and 43A, includes a stage mainsection 91A, and a wafer table WTB1 mounted on stage main section 91A.Stage main section 91A, as shown in FIG. 43A, has a mover 56 whichconfigures a planar motor 151 along with a stator 152 embedded insidebase board 12, and an air slider 54, which is arranged integrally in theperiphery of the lower half section of mover 56 and has a plurality ofair bearings.

Mover 56 is configured, for example, by a magnet unit including a planarmagnetism generating body consisting of a plurality of flat platemagnets having a matrix arrangement so that the polarity of adjacentpole faces are different from one another. Mover 56 has a thinrectangular solid shape.

Meanwhile, stator 152 is configured by an armature unit having aplurality of armature coils (drive coils) 57 disposed in a matrix in theinterior of base board 12. As armature coil 57, in the fourthembodiment, an X drive coil and a Y drive coil are arranged. And, bystator 152 consisting of the armature unit including the plurality of Xdrive coils and Y drive coils and mover 56 consisting of the magnet unitpreviously described, a moving magnet type planar motor 151 by anelectromagnetic drive method (Lorentz force drive method) is configured.

A plurality of armature coils 57 is covered by a tabular member 58 madeof a non-magnetic material that configures the upper surface of baseboard 12. The upper surface of tabular member 58 configures a pressurereceiving surface of pressurized air from air bearings which themovement guide surface of wafer stage WST1 and WST2 and air slider 54are equipped with.

Wafer table WTB1 has three sections which are a table main section 34consisting of a thin rectangular (a thick plate-shaped) member, an FDbar 46 attached (to be precise, kinematically supported by table mainsection 34 by a full-kinematic mount structure) to the side surface onthe +Y side of table main section 34, and a measurement section 138fixed to the side surface on the −Y side of table main section 34.Hereinafter, table main section 34, FD bar 46, and measurement section138 will be referred to as wafer table WTB1 as a whole, besides the casewhen specifying is especially necessary. In this case, table mainsection 34 has the same shape and outer shape size as mover 56 whenviewed from above.

Wafer table WTB1 is mounted on stage main section 91A via a Z levelingmechanism (not shown) (for example, including voice coil motors and thelike), which configures a part of stage drive system 124. Wafer tableWTB1 is driven finely in the Z-axis direction, the ex direction, and theθy direction with respect to stage main section 91A by the Z levelingmechanism. Accordingly, wafer table WTB1 is drivable in directions ofsix degrees of freedom (X, Y, Z, θx, θy, and θz) with respect to baseboard 12, by stage drive system 124 (refer to FIG. 47) including planarmotor 151 and the Z leveling mechanism.

In the center of the upper surface of wafer table WTB1, a wafer holder(not shown) is arranged which holds the wafer by vacuum suction or thelike. On the outer side of the wafer holder (mounting area of thewafer), as shown in FIG. 43B, a plate 28 is arranged that has a circularopening one size larger than the wafer holder formed in the center, andalso has a rectangular outer shape (contour). A liquid repellenttreatment against liquid Lq is applied to the surface of plate 28.Incidentally, plate 28 is set so that its entire surface becomessubstantially flush with the surface of wafer W. Further, FD bar 46 andmeasurement section 138 are attached to table main section 34 so thateach of their surfaces becomes substantially flush with the surface ofplate 28.

Further, a rectangular opening is formed substantially at the center inthe X-axis direction of plate 28 in the vicinity of the +Y side end, andinside the opening, a measurement plate 30 is embedded. And, below eachof a pair of aerial image measurement slit patterns SL of measurementplate 30 inside wafer table WTB1, a pair of aerial image measuringdevices 45A (refer to FIG. 47) including an optical system including anobject lens and the like and a light receiving element (for example, aphotomultiplier tube and the like) is arranged corresponding to the pairof aerial image measurement slit patterns SL described above. As aerialimage measuring device 45A, a device having a configuration similar tothe one that is disclosed in, for example, U.S. Patent ApplicationPublication No. 2002/0041377 and the like is used. Measurement plate 30has its surface arranged substantially flush with plate 28.

Furthermore, in the area on the upper surface of plate 28 on one sideand the other side (on the right and left sides in FIG. 43B) in theX-axis direction, moving scales 39A and 39B are formed. Moving scales39A and 39B are each configured of a reflection type two-dimensionalgrating (for example, a diffraction grating), which is, for example, agrating having a periodic direction in the Y-axis direction and agrating having a periodic direction in the X-axis direction combined.The pitch of the grid lines of the two-dimensional diffraction gratingsis, for example, 1 μm, for both the Y-axis direction and the X-axisdirection. Incidentally, in FIG. 43B, the pitch of the gratings isillustrated larger than the actual pitch for the sake of convenience.The same is true also in other drawings. Moving scales 39A and 39B arecovered with a liquid repellent film (water repellent film).

Incidentally, in order to protect the diffraction grating, it is alsoeffective to cover the grating with a glass plate with low thermalexpansion that has water repellency. In this case, as the glass plate, aplate whose thickness is the same level as the wafer, such as forexample, a plate 1 mm thick, can be used, and the plate is set on theupper surface of table main section 34 (wafer table WTB1) so that thesurface of the glass plate becomes the same height (surface position) asthe wafer surface.

Incidentally, near the edge of each scale of plate 28, a pattern forpositioning (not shown) is arranged for deciding the relative positionbetween an encoder head and a scale (to be described later). The patternfor positioning is configured, for example, from grid lines that havedifferent reflectivity, and when the encoder head scans the pattern, theintensity of the output signal of the encoder changes. Therefore, athreshold value is determined beforehand, and the position where theintensity of the output signal exceeds the threshold value is detected.Then, the relative position between the encoder head and the scale isset, with the detected position as a reference.

As described above, in the fourth embodiment, because plate 28 itselfconstitutes the scale, a glass plate with low-thermal expansion is usedas plate 28. However, besides such a plate, a scale member made up of aglass plate or the like with low-thermal expansion on which a grating isformed can also be fixed on the upper surface of wafer table WTB1, forexample, by a plate spring (or vacuum suction) or the like so as toprevent local shrinkage/expansion. Or, wafer table WTB1 can also beformed by materials with a low-thermal expansion, and in such a case,the moving scales may be directly formed on the upper surface of wafertable WTB1.

FD bar 46 is configured similar to the first embodiment previouslydescribed, as shown in FIG. 43B. The distance between a pair ofreference gratings 52 formed on FD bar 46 is referred to as a distanceL.

Measurement section 138 is a rectangular solid shape whose longitudinaldirection is in the X-axis direction. In measurement section 138,members for various measurements which will be described later on arearranged.

Wafer stage WST2, as shown in FIGS. 42, 44A, and 44B and the like,includes stage main section 91B and a wafer table WTB2, and isconfigured in a similar manner with wafer stage WST1 described above.Wafer stage WST2 is driven by planar motor 151 consisting of mover 56and stator 152.

As shown in FIGS. 44A and 44B, wafer table WTB2 has three sections whichare a table main section 34, and an FD bar 46 and a measurement section138 which are attached to the side surfaces on the side and the −Y sideof table main section 34, respectively, as in wafer table WTB1previously described. However, the members for various measurementsequipped in measurement section 138 of wafer stage WST2 is differentfrom the members for various measurements equipped in measurementsection 138 of wafer stage WST1. More specifically, in the fourthembodiment, members for a plurality of types of measurement are placeddispersed at measurement sections 138 that wafer stages WST1 and WST2each have. Incidentally, in the description below, the pair of aerialimage measuring devices configured including measurement plate 30 ofwafer table WTB2 will be described as aerial image measuring device 45B.

As the members used for the measurements described above, for example,an uneven illuminance measuring sensor 94 as in the previous descriptionand an illuminance monitor 97 which has a light-receiving section of apredetermined area to receive illumination light IL on the image planeof projection optical system PL as shown in FIG. 43B, and a wavefrontaberration measuring instrument 98 and an aerial image measuringinstrument as shown in FIG. 44B and the like can be used.

In the fourth embodiment as well, as the measurement members, forexample, a member such as a transmittance measuring instrument thatmeasures the transmittance of projection optical system PL, and/or ameasuring instrument that observes local liquid immersion device 8previously described, such as, for example, nozzle unit 32 (or tip lens191) and the like can be used. Furthermore, members different from themeasurement members such as a cleaning member that cleans nozzle unit32, tip lens 191 or the like may also be mounted on either one of thewafer stages.

Incidentally, also in the fourth embodiment, liquid immersion exposureis performed in which wafer W is exposed with exposure light(illumination light) IL via projection optical system PL and liquid(water) Lq, and accordingly, uneven illuminance measuring sensor 94,illuminance monitor 97, wavefront aberration measuring instrument 98,and the aerial image measuring instrument that are used in measurementusing illumination light IL receive illumination light IL via projectionoptical system PL and water. Further, a part of each sensor, such as,for example, the optical system, can be mounted on the wafer table, orthe whole sensor may be placed on the wafer table. The same can be saidfor aerial image measuring devices 45A and 45B previously described.

Incidentally, although it is omitted in the drawings, a wiring/pipingcable (not shown) connects from the −X side end of wafer stage WST1 to afirst cable shuttle (not shown) movable in the Y-axis direction arrangedon the −X side of base board 12. Similarly, a wiring/piping cable (notshown) connects from the +X side end of wafer stage WST2 to a secondcable shuttle (not shown) movable in the Y-axis direction arranged onthe +X side of base board 12. By these cables, power supply to the Zleveling mechanism, the measurement members and the like, and the supplyof pressurized air to the air sliders and the like arranged in bothwafer stages WST1 and WST2 are performed.

In exposure apparatus 1000 of the fourth embodiment, although it isomitted in FIG. 42 from the viewpoint of avoiding intricacy of thedrawing, in actual practice, as shown in FIG. 45, a primary alignmentsystem AL1 having a detection center at a position spaced apart fromoptical axis AX at a predetermined distance on the −Y side is placed, ona straight line that passes through the center (an optical axis AX ofprojection optical system PL, also coincides with the center of exposurearea IA previously described in the fourth embodiment) of projectionunit PU and is also parallel to the Y-axis, or more specifically, onreference axis LV₀. Further, on one side and the other side in theX-axis direction with primary alignment system AL1 in between, secondaryalignment systems AL2 ₁ and AL2 ₂, and AL2 ₃ and AL2 ₄ whose detectioncenters are substantially symmetrically placed with respect to referenceaxis LV₀ are severally arranged. That is, five alignment systems AL1 andAL2 ₁ to AL2 ₄ are placed so that their detection centers are atdifferent positions in the X-axis direction, or more specifically,placed along the X-axis direction.

As each of primary alignment system alignment system. AL1, and secondaryalignment systems AL2 ₁ to AL2 ₄, for example, an FIA (Field ImageAlignment) system by an image processing method is used. The imagingsignal from each of primary alignment system AL1 and the four secondaryalignment systems AL2 ₁ to AL2 ₄ is supplied to main controller 20 inFIG. 47, via an alignment signal processing system (not shown)

Next, a configuration and the like of interferometer system 118 whichmeasures the positional information of wafer stages WST1 and WST2 willbe described.

On a surface on the +X side (the +X end surface) and a surface on the −Xside (the −X end surface) of wafer table WTB1, respectively,mirror-polishing is applied and reflection surfaces 27 a and 27 c shownin FIG. 43B are formed. Further, on a surface on the +Y side (the +Y endsurface) of wafer table WTB1, or more specifically, the +Y end surfaceof FD bar 46, and on a surface on the −Y side (the −Y end surface) ofwafer table WTB1, or more specifically, the −Y end surface ofmeasurement section 138, reflection surfaces 27 b and 27 d are formed,respectively.

Similarly, mirror-polishing is applied to each of the +X end surface,the −X end surface, the +Y end surface (the +Y end surface of the FDbar), and the −Y end surface (the −Y end surface of the measurementsection) of wafer table WTB2, and reflection surfaces 27 e, 27 g, 27 f,and 27 h shown in FIG. 44B are formed, respectively.

As shown in FIG. 46, interferometer system 118 includes four Yinterferometers 206, 207, 208, and 209, and six X interferometers 217,218, 226, 227, 228, and 229. Y interferometers 206, 207, and 208 areplaced on the +Y side of base board 12, at different positions in theX-axis direction. Y interferometer 209 is placed on the −Y side of baseboard 12, facing Y interferometer 207. X interferometers 217 and 218 areplaced on the −X side of base board 12, at a predetermined distance inthe Y-axis direction. Further, X interferometers 226, 227, 228, and 229are placed at different positions in the Y-axis direction on the +X sideof base board 12. Of these interferometers, X interferometers 227 and228 are placed, facing X interferometers 217 and 218, respectively.

To enter the details, as shown in FIG. 46, Y interferometer 207 is amultiaxial interferometer which uses reference axis LV₀ previouslydescribed as a substantial measurement axis in the Y-axis direction. Yinterferometer 207 irradiates at least three measurement beams parallelto the Y-axis on reflection surface 27 b (or reflection surface 27 f ofwafer table WTB2) of wafer table WTB1, and receives the reflected lightsthereof and measures positional information of reflection surface 27 b(or 27 f) in the Y-axis direction at the irradiation points of eachmeasurement beam. Such positional information is sent to main controller20 (refer to FIG. 47). Main controller 20 computes a position (Yposition) in the Y-axis direction, θz rotation quantity (yawing amount),and θx rotation quantity (pitching amount) of wafer table WTB1 (orWTB2), based on positional information measured with Y interferometer207.

Y interferometers 206, 208, and 209 are used in a similar manner as Yinterferometer 207 to measure the Y position, pitching amount, andyawing amount of wafer table WTB1 (or WTB2). Y interferometers 206 and208 have substantial measurement axes LV₁ and LV₂ in the Y-axisdirection, which are parallel to reference axis LV₀, respectively.Further, Y interferometer 209 uses reference axis LV₀ as the substantialmeasurement axis, and irradiates at least three measurement beams onreflection surface 27 d of wafer table WTB1 or on reflection surface 27h of wafer table WTB2.

X interferometers 217 and 227 are multiaxial interferometers which usereference axis LH previously described as substantial measurement axesin the X-axis direction. More specifically, X interferometer 217irradiates a plurality of measurement beams parallel to the X-axis onreflection surface 27 c of wafer table WTB1, and receives each of thereflected lights and measures positional information of reflectionsurface 27 c in the X-axis direction at the irradiation points of eachmeasurement beam. Similarly X interferometer 227 irradiates a pluralityof measurement beams parallel to the X-axis on reflection surface 27 eof wafer table WTB2, and receives each of the reflected lights andmeasures positional information of reflection surface 27 e in the X-axisdirection at the irradiation points of each measurement beam. Suchpositional information is sent to main controller 20. Main controller 20computes the X position and the θy rotation quantity (rolling amount) ofwafer table WTB1 and WTB2, based on positional information measured by Xinterferometers 217 and 227, respectively.

X interferometers 218 and 228 consist of multiaxial interferometerssimilar to X interferometers 217 and 227, and are each used to measurethe X position and the θy rotation quantity (rolling amount) of wafertables WTB1 and WTB2, respectively.

The remaining X interferometers 226 and 229 consist of multiaxialinterferometers similar to X interferometers 217 and 227, and are usedtogether to measure the X position and the θy rotation quantity (rollingamount) of wafer tables WTB1 and WTB2. Incidentally, X interferometer229 uses reference axis LA previously described as a measurement axis.

By using interferometer system 118 including Y interferometers 206, 207,208, and 209 and X interferometers 217, 218, 226, 227, 228, and 229 asdescribed, positional information of wafer tables WTB1 and WTB2 indirections of five degrees of freedom (X, Y, θx, θy, and θz) can bemeasured. Incidentally, the multiaxial interferometers, such as, forexample, each of the X interferometers, can irradiate a laser beam on areflection surface (not shown) arranged in a part of a mainframe holdingprojection unit PU via a reflection surface set on wafer stages WST1 andWST2 inclined at an angle of 45 degrees, and can detect the Z positionof wafer stages WST1 and WST2.

Next, the structure and the like of encoder system 150 which measurespositional information (including information on the θz rotation) ofwafer stages WST1 and WST2 in the XY plane will be described.

In exposure apparatus 1000 of the fourth embodiment, as shown in FIG.45, two head units 162A and 162B of encoder system 150 are placed on the+X side and −X side of liquid immersion area 14 (nozzle unit 32)previously described with the X-axis direction serving as thelongitudinal direction. Although illustration of head units 162A and162B is omitted in FIG. 45 and the like from the viewpoint of avoidingintricacy of the drawings, in actual practice, head units 162A and 162Bare fixed to the main frame previously described that holds projectionunit PU in a suspended state via a support member.

Head units 162B and 162A are each equipped with a plurality of (five, inthis case) two-dimensional encoder heads (hereinafter, shortly referredto as 2D heads) 164 _(i) and 165 _(j) (i, j=1 to 5) that are placed at adistance WD in the X-axis direction. More particularly, head units 162Band 162A are each equipped with a plurality of (four, in this case) 2Dheads (164 ₁ to 164 ₄ or 165 ₂ to 165 ₅) that are placed on referenceaxis LH previously described at distance WD except for the periphery ofprojection unit PU, and a 2D head (164 ₅ or 165 ₁) which is placed at aposition a predetermined distance away in the −Y direction fromreference axis LH in the periphery of projection unit PU, or morespecifically, on the −Y side of nozzle unit 32. Head units 162A and 162Bare each also equipped with five Z heads which will be described lateron. A two-dimensional encoder (a 2D encoder) herein is an encoder headwhich has sensibility in two axial directions in directions orthogonalto each other, in this case, the X-axis direction and the Y-axisdirection, or more specifically, an encoder head whose measurementdirection is in the directions of the two orthogonal axes. As the 2Dhead, for example, a 2D head which has a configuration similar to the 2Dhead employed in the second and third embodiments previously described(for example, the head shown in FIG. 34) can be used.

Head unit 162A constitutes a multiple-lens (five-lens, in this case)two-dimensional encoder (hereinafter appropriately shortened to“encoder”) 170A (refer to FIG. 47) that measures the position of waferstages WST1 and WST2 in the X-axis direction (the X position) and theY-axis direction (the Y position) using moving scale 39A previouslydescribed. Similarly, head unit 162B constitutes a multiple-lens(five-lens, in this case) two-dimensional encoder 170B (refer to FIG.47) that measures the X position and Y position of wafer stages WST1 andWST2 using moving scale 39B previously described, in this case, distanceWD in the X-axis direction of the five 2D heads (164 _(i) or 165 _(j))(more particularly, the measurement beams) that head units 162A and 162Bare each equipped with, is set slightly narrower than the width ofmoving scales 39A and 39B (or more precisely, the two-dimensionalgratings) in the X-axis direction.

Further, at a position a predetermined distance away in the −Y directionfrom 2D heads 164 ₃ and 165 ₃, 2D heads 166 ₁ and 166 ₂ are placed. 2Dheads 166 ₁ and 166 ₂ are arranged in a placement symmetric to eachother with respect to reference axis LV₀. In actual practice, the 2Dheads 166 ₁ and 166 ₂ are fixed to the main frame previously describedthat holds projection unit PU in a suspended state, via a supportmember.

2D heads 166 ₂ and 166 ₁ constitute two-dimensional encoders 1705 and170F (refer to FIG. 47) that measure the X position and the Y positionof wafer stages WST1 and WST2 using moving scales 39A and 39B previouslydescribed, respectively. On periphery edge exposure operation and thelike which will be described later on, 2D heads 1661 and 1662 facemoving scales 39B and 39A, respectively, and the X and Y positions, andthe θz rotation quantity of wafer stage WST1 or WST2 are measured by 2Dheads 166 ₁ and 166 ₂ (more specifically, two-dimensional encoders 170Eand 170F).

In the embodiment, head units 162C and 162D are respectively arranged apredetermined distance away further on the −Y side of 2D heads 166 ₂ and166 ₁. Although illustration of head units 162C and 162D is omitted inFIG. 45 and the like from the viewpoint of avoiding intricacy of thedrawings, in actual practice, head units 162C and 162D are fixed to themain frame previously described that holds projection unit PU in asuspended state via a support member.

Head unit 1620 is equipped with five 2D heads 167 ₁ to 167 ₅, which areeach placed at the same X position as the five 2D heads 64 to 64belonging to head unit 162B. More particularly, head unit 162D isequipped with four 2D heads 167 ₁ to 167 ₄ placed on the −X side of thesecondary alignment system AL2 ₁ on reference axis LA previouslydescribed at a distance WD, and one 2D head 167 ₅, which is placed at aposition on the −Y side of the secondary alignment system AL2 ₁ locatedaway on the side from the innermost (the +X side) 2D head 167 ₄ by adistance WD and is also a predetermined distance away to the −Y sidefrom reference axis LA.

Head unit 1620 is symmetrical to head unit 162D with respect toreference axis LV₀ previously described, and is equipped with five 2Dheads 168 ₁ to 168 ₅ which are placed in symmetry to five 2D heads 167 ₅to 167 ₁ with respect to reference axis LV₀. On alignment operation andthe like which will be described later on, at least one each of 2D heads167 _(p) and 168 _(q) (p, q=1 to 5) faces moving scales 39B and 39A,respectively, and by such 2D heads 167 and 168 (more specifically,two-dimensional encoders 170D and 170C (refer to FIG. 47) which areconfigured by these 2D heads 167 and 168) the X, Y positions, and the θzrotation of wafer stages WST1 and WST2 are measured. In this case, thedistance in the X-axis direction of 2D heads 167 ₄ and 168 ₂ adjacent tothe secondary alignment systems AL2 ₁ and AL2 ₄ in the X-axis directionis also set approximately equal to distance L previously described.

Further, in the fourth embodiment, a baseline measurement of thesecondary alignment systems AL2 ₁ to AL2 ₄ is performed in a proceduresimilar to Sec-BCHK (interval) disclosed in, for example, the pamphletof International Publication 2007/097379, regularly. At the time of baseline measurement of the secondary alignment systems AL2 ₁ to AL2 ₄, thetwo 2D heads 167 ₄ and 168 ₂ described above face a pair of referencegratings 52 of FD bar 46, respectively, and by the 2D heads 167 ₄ and168 ₂ which face the pair of reference gratings 52, the Y position of FDbar 46 is measured at the position of each reference grating 52. In thedescription below, the encoders configured by 2D heads 167 ₄ and 168 ₂which face the pair of reference gratings 52, respectively, are referredto as Y linear encoders (also shortly referred to as “Y encoders” or“encoders” as needed) 170G and 170H (refer to FIG. 47)

The encoders 170A to 170H described above measure the positioncoordinates of wafer stages WST1 (or WST2) at a resolution of, forexample, around 0.1 nm, and the measurement values are supplied to maincontroller 20. Main controller 20 controls the XY position (includingthe θz rotation) of wafer stage WST1 (or WST2) within the XY plane basedon the measurement values of encoders 170A and 170B, or 170C and 170D,or 170E and 170F, as well as control the θz rotation of FD bar 46 (waferstage) based on the measurement values of Y encoders 170G and 170H.

In the fourth embodiment, as 2D heads 164 _(i), 165 _(j), 166 ₁, 166 ₂,167 _(p), and 168 _(q) described above, for example, an encoder is usedof a diffraction interference mode using three gratings, which has twopairs of fixed scales placed in the X-axis direction and the Y-axisdirection, and converges diffraction lights of the same order in thedirections of the two orthogonal axes generated from the two-dimensionalgratings (moving scales 39A and 39B) on each pair of the fixed scales,respectively, on a common index scale. However, besides such a head, a2D head having any configuration can be used, as long as the XYtwo-dimensional position of the wafer table can be measured with asingle head.

In exposure apparatus 1000 of the fourth embodiment, a multipoint AFsystem consisting of an irradiation system 90 a and a photodetectionsystem 90 b is arranged as shown in FIG. 45. In this case, as anexample, irradiation system 90 a is placed on the +Y side of head unit162D previously described, and photodetection system 90 b is placed onthe +Y side of head unit 162C previously described in a state opposingirradiation system 90 a. Irradiation system 90 a and photodetectionsystem 90 b are placed symmetric to each other, with respect toreference axis LV₀.

In FIG. 45, the plurality of detection points to which a detection beamis severally irradiated are not individually shown, but are shown as anelongate detection area (beam area) AF that extends in the X-axisdirection between irradiation system 90 a and photodetection system 90b. Because the length of detection area AF in the X-axis direction isset slightly longer than the diameter of the wafer (W1 and W2) positioninformation (surface position information) in the Z-axis directionacross the entire surface of the wafer can be measured by only scanningthe wafer once in the Y-axis direction. Further, since detection area AFis placed between liquid immersion area 14 (exposure area IA) and thedetection areas of the alignment systems (AL1, AL2 ₁, AL2 ₂, AL2 ₃ andAL2 ₄) in the Y-axis direction, the detection operations of themultipoint AF system and the alignment systems can be performed inparallel. The multipoint AF system 90 is arranged on the mainframe andthe like that holds projection unit PU.

Regarding a straight line LF in the X-axis direction passing through thecenter in the Y-axis direction of detection area AF of the multipoint AFsystem (90 a, 90 b), a pair of head units 162E and 162F are placed in aplacement almost symmetric to the pair of head units 162C and 162D. Headunits 162E and 162F are fixed to the lower surface of the mainframe (notshown). Head units 162E and 162F are arranged in a symmetric placementwith respect to reference axis LV₀. Head unit 162F has 2D heads 167 ₁ to167 ₅ belonging to head unit 162D previously described, and five Z heads171 ₁ to 171 ₅ which are placed symmetrical with respect to straightline LF. Further, head unit 162E has 2D heads 168 ₁ to 168 ₅ belongingto head unit 162C previously described, and five Z heads 173 ₁ to 173 ₅which are placed symmetrical with respect to straight line LF. In thiscase, Z heads 171 ₁ to 171 ₅ and Z heads 173 ₅ to 173 ₁ are placedsymmetrically with respect to reference line LV₀ described.

As Z heads 171 ₁ to 171 ₅ and Z heads 173 ₁ to 173 ₅, a sensor head thatirradiates a light on wafer table WTB1 or WTB2, or to be more specific,on moving scales 39A and 39B, from above, receives the reflected lightand measures position information of the wafer table WTB1 or WTB2surface in the Z-axis direction at the irradiation point of the light,as an example, a head of an optical displacement sensor (a sensor headby an optical pickup method), which has a configuration like an opticalpickup used in a CD drive device, is used.

Furthermore, head units 162B and 162A previously described arerespectively equipped with five Z heads 74 _(i) and 76 _(j) (i, j=1 to5), which are five heads each, at the same X position as Y heads 164_(i) and 165 _(j) (i, j=1 to 5) respectively equipped in head units 162Band 162A, with the Y position shifted. In this case, Z heads 76 ₂ to 76₅ and 74 ₁ to 74 ₄, which are four heads each on the outer sidebelonging to head units 162A and 162B, respectively, are placed parallelto reference axis LH a predetermined distance away in the +Y directionfrom reference axis LH. Further, Z heads 76 ₁ and 74 ₅, which are headson the innermost side belonging to head units 162A and 162B,respectively, are placed on the +Y side of projection unit PU. And Zheads 74 _(i), 76 _(j) (i, j=1 to 5), which are five heads eachbelonging to head unit 162B and 162A, respectively, are placed symmetricto each other with respect to reference axis LV₀.

Z heads 171 ₁ to 171 ₅, Z heads 173 ₁ to 173 ₅, Z heads 74 ₁ to 74 ₅,and Z heads 76 ₁ to 76 ₅ described above connect to main controller 20via a signal processing/selection device 160, as shown in FIG. 47. Maincontroller 20 selects an arbitrary Z head from 171 ₁ to 171 ₅, Z heads173 ₁ to 173 ₅, Z heads 74 ₁ to 74 ₅, and Z heads 76 ₁ to 76 ₅ viasignal processing/selection device 160 and makes the head move into anoperating state, and then receives the surface position informationdetected by the Z head which is in the operating state via signalprocessing/selection device 160. In the fourth embodiment, a surfaceposition measurement system 180 that measures positional information ofwafer table WTB1 (or WTB2) in the Z-axis direction and the direction ofinclination with respect to the XY plane is configured, including Zheads 171 ₁ to 171 ₅, Z heads 173 ₁ to 173 ₅, Z heads 74 ₁ to 74 ₅, andZ heads 76 ₁ to 76 ₅, and signal processing/selection device 160.

Furthermore, in exposure apparatus 1000 of the fourth embodiment, aperiphery edge exposure unit 51 (refer to FIG. 8) having an active mask51 a used for periphery edge exposure extending in the X-axis directionis placed in between 2D heads 166 ₁ and 166 ₂ previously described, asshown in FIG. 45. Periphery edge exposure unit 51 is supported in asuspended state via a support member (not shown) on the lower surface ofthe mainframe (not show). In periphery edge exposure unit 51, byswitching each micro mirror that constitute a pair of variable shapedmasks VM1 and VM2 of the active mask used for periphery edge exposurebetween an ON state and an OFF state, any areas of the periphery shotson wafer W1 (or W2) positioned below periphery edge exposure unit 51 canbe exposed. Incidentally, active mask 51 a used for periphery edgeexposure of periphery edge exposure unit 51 can be configured by asingle variable shaped mask which extends in the X direction. Further,instead of the light from the light source, for example, an opticalfiber can be used to guide illumination light IL to the active mask usedfor periphery edge exposure.

According to periphery edge exposure unit 51, by moving wafer stage WST1or WST2 in the Y-axis direction in a state where the center of wafer W1or W2 in the X-axis direction and the center of periphery edge exposureunit 51 in the longitudinal direction almost coincide with each other,an arbitrary pattern can be formed by exposing an arbitrary peripheryedge exposure area (for example, refer to areas S1 a, S7 a, S8 a, S16 a,S17 a, S27 a, S50 a, S60 a, S61 a, S69 a, S70 a, and S76 a in FIG. 13)of wafer W1 or W2.

FIG. 47 shows the main configuration of the control system of exposureapparatus 1000. The control system is mainly configured of maincontroller 20 composed of a microcomputer (or workstation) that performsoverall control of the entire apparatus. Incidentally, in FIG. 47,various sensors such as uneven illuminance measuring sensor 94,illuminance monitor 97, and wavefront aberration measuring instrument 98previously described are collectively shown as a sensor group 99.

Next, a parallel processing operation that uses wafer stage WST1 andwafer stage WST2 will be described, based on FIGS. 48 to 76.Incidentally, during the operation described below, main controller 20controls liquid supply device 5 and liquid recovery device 6 so thatliquid Lq is supplied to the space under tip lens 191 of projectionoptical system PL as well as is recovered from the space directly undertip lens 191, and a constant quantity of liquid Lq is held between tiplens 191 and wafer table WTB1 and/or WTB2, which constantly forms liquidimmersion area 14. However, in the description below, for the sake ofsimplicity, the explanation related to the control of liquid supply unit5 and liquid recovery unit 6 will be omitted. Further, many drawings areused in the operation description hereinafter, however, reference codesmay or may not be given to the same member for each drawing. Morespecifically, the reference codes written are different for eachdrawing, however, such members have the same configuration, regardlessof the indication of the reference codes. The same can be said for eachdrawing used. In the description so far. Incidentally, in FIGS. 48 to76, only liquid immersion area 14 is illustrated for the sake ofconvenience, and projection unit PU (projection optical system PL),local liquid immersion device 8 (nozzle unit 22) and the like areomitted.

FIG. 48 shows a state in which exposure by the step-and-scan method isperformed on wafer W2 mounted on wafer stage WST2 below liquid immersionarea 14 (projection unit PU), and wafer exchange performed between awafer carriage mechanism (not shown) and wafer stage WST1, cooling of awafer holder, and other preparatory operations for exposure (hereinafterreferred to as a Pit operation) have been concurrently performed at aleft-side loading position. At this point, the position of wafer tableWTB1 is controlled by main controller 20, based on measurement values ofY interferometer 208 and X interferometer 229. Further, at this point,the position (including rotation quantity in the θz direction) withinthe XY plane of wafer table WTB2 is controlled by main controller 20,based on measurement values of 2D heads 165 _(j) and 164 _(i) (morespecifically, two-dimensional encoders 170A and 170B) belonging to headunits 162A and 162B, respectively facing moving scales 39A and 39B ofwafer table WTB2.

Further, the position in the Z-axis direction and rotation (rolling) inthe θy direction of wafer table WTB2 which is being exposed iscontrolled by main controller 20, based on measurement values of a pairof Z head 74 i and 76 j which respectively face the ends on the wafertable WTB2 surface on one side and the other side (movement scale 39B,39A) in the X-axis direction. Further, the rotation (pitching) in the exdirection of wafer table WTB2 which is being exposed is controlled bymain controller 20, based on measurement values of Y interferometer 207.The control (the focus leveling control of wafer W) of the position ofwafer table WTB2 in the Z-axis direction, the θy rotation, and the θxrotation during this exposure is performed, based on results of a focusmapping performed beforehand. Furthermore, the position wafer table WTB2in directions of five degrees of freedom, except for the Z-axisdirection, is also measured by interferometers 207 and 227.

The exposure operation described above is performed by main controller20, based on results of wafer alignment (for example, EGA) that has beenperformed beforehand and on the latest baseline and the like ofalignment systems AL1, and AL2 ₁ to AL2 ₄, by repeating a movementoperation between shots in which wafer stage WST is moved to a scanningstarting position (an acceleration starting position) for exposure ofeach shot area on wafer W2, and a scanning exposure operation in which apattern formed on reticle R is transferred onto each shot area by ascanning exposure method. Incidentally, the number of rows of shot areassubject to exposure on wafer W2 is even, and in the exposure describedabove, exposure is performed in a complete alternate scan, in the orderfrom a shot area located on the upper left side in FIG. 48 to a shotarea located on the lower left side.

While exposure by the step-and-scan method of wafer W2 on wafer tableWTB2 is being continued in the manner described above, main controller20 begins the drive of wafer stage WST1 in the +X direction, as shown inFIG. 49. And, wafer stage WST1 is moved to a position where a referencemark FM on measurement plate 30 is positioned within a field (adetection area) of primary alignment system AL1, as shown in FIG. 50.During this movement, main controller 20 switches the control of theposition of wafer table WTB1 within the XY plate from a control based onmeasurement values of interferometers 208 and 229 previously describedto a control based on 2D heads 167 _(p) and 168 _(q) (p, q=1 to 5)belonging to head units 162D and 162C facing moving scales 39B and 39Aof wafer table WTB1, or more specifically, to a control based onmeasurement values of two-dimensional encoders 170D and 170C.

Then, when wafer stage WST1 moves to the position shown in FIG. 50, maincontroller 20 performs a reset (origin reset) of Y interferometer 209, Xinterferometer 229, and two-dimensional encoders 170D and 170C, prior tostarting wafer alignment (and other preprocessing measurements) of a newwafer W1.

When the reset of interferometers 209, 229, and two-dimensional encoders170D and 170C are completed, main controller 20 uses primary alignmentsystem AL1 to detect reference mark FM on measurement plate 30 of waferstage WST1. And, main controller 20 detects the position of referencemark FM with the index center of primary alignment system AL1 serving asa reference, and makes a link between the detection results and themeasurement values of encoders 170C and 170D at the time of thedetection, and then stores them in memory.

Next, main controller 20 begins the scanning (scan) of wafer stage WST1in the direction, and moves wafer stage WST1 to the alignment area, asshown in FIG. 51. Then, main controller 20 begins enhanced globalalignment (EGA) using encoders 170C and 170D (and interferometers 209and 229), while measuring the position coordinates of wafer stage WST2.More specifically, while wafer stage WST1 is moved in the X-axisdirection and a step movement in the Y-axis direction is also performed,main controller 20 detects a part of a plurality of alignment marksarranged in a plurality of shot areas (sample shot areas) which arespecified on wafer W1 using at least one alignment system that includesprimary alignment system AL1 for each step position, and makes a linkbetween the detection results and the measurement values of encoders170C and 170D at the time of the detection, and then stores them inmemory (not shown).

FIG. 51 shows a state where alignment marks arranged in four sample shotareas are detected almost simultaneously and individually, using primaryalignment system AL1, and secondary alignment systems AL2 ₂, AL2 ₃, andAL2 ₄ (refer to the star-shaped marks in FIG. 51). At this point,exposure by the step-and-scan method of wafer W2 held on wafer tableWTB2 is being continued.

After the scanning (scan) of wafer stage WST1 in the +Y direction beginsin the manner described above until wafer stage WST1 moves in the +Ydirection and detection beams of multipoint AF system (90 a, 90 b) beginto irradiate wafer W1, main controller 20 activates (turns ON) two Zheads 171 _(p) and 173 _(q) (for example, 171 ₃ and 173 ₃) that facemoving scales 39B and 39A, respectively, and multipoint AF system (90 a,90 b) together, and begins focus mapping.

In this case, focus mapping in the fourth embodiment refers to a processof taking in positional information (surface position information) inthe Z-axis direction of the surface (the surface of plate 28, or to bespecific, the surface of moving scales 39B and 39A) of wafer table WTB1(or WTB2) measured by Z heads 171 _(p) and 173 _(q) and positionalinformation (surface position information) in the Z-axis direction ofthe surface of wafer table WTB1 (or WTB2) at a plurality of detectionpoints detected by multipoint AF system (90 a, 90 b) at a predeterminedsampling interval, in a state where Z heads 171 _(p) and 173 _(q) andmultipoint AF system (90 a, 90 b) are operating simultaneously and whilewafer stage WST1 (or WST2) is proceeding in the +Y direction (refer toFIGS. 51 to 55), making each surface position information which has beentaken in and the measurement values of encoders 170C and 170D at thetime of each sampling correspond to one another, and then sequentiallystoring the information in memory (not shown).

After the focus mapping has started, main controller 20 moves waferstage WST1 in the +Y direction by a predetermined distance as well as inthe −X direction by a predetermined distance based on the measurementvalues of encoders 170C and 170D, and sets the position of wafer stageWST1 at a position where five alignment systems AL1, and AL2 ₁ to AL2 ₄can detect alignment marks arranged in five sample shot areas on wafer Walmost simultaneously and individually, as shown in FIG. 52. Then, maincontroller 20 detects the five alignment mark substantially at the sametime as well as individually (refer to the star-shaped marks in FIG.52), using the five alignment systems AL1, and AL2 ₁ to AL2 ₄, and makesa link between the detection results of the five alignment systems AL1,and AL2 ₁ to AL2 ₄ and the measurement values of encoders 170C and 170Dat the time of the detection, and then stores them in memory (notshown). At this point, focus mapping performed on the wafer stage WST1side, and exposure by the step-and-scan method of wafer W2 held on wafertable WTB2 previously described are being continued.

Next, main controller 20 moves wafer stage WST1 in the +Y direction by apredetermined distance as well as in the +X direction by a predetermineddistance based on the measurement values of encoders 170C and 170D, andsets the position of wafer stage WST1 at a position where five alignmentsystems AL1 and AL2 ₁ to AL2 ₄ can detect alignment marks arranged infive sample shot areas on wafer W almost simultaneously andindividually, as shown in FIG. 53. Then, main controller 20 detects thefive alignment mark substantially at the same time as well asindividually (refer to the star-shaped marks in FIG. 5), using the fivealignment systems AL1, and AL2 ₁ to AL2 ₄, and makes a link between thedetection results of the five alignment systems AL1, and AL2 ₁ to AL2 ₄and the measurement values of encoders 170C and 170D at the time of thedetection, and then stores them in memory (not shown). At this point,focus mapping performed on the wafer stage WST1 side, and exposure bythe step-and-scan method of wafer W2 on wafer table WTB2 previouslydescribed are being continued.

Next, main controller 20 moves wafer stage WST1 in the +Y direction by apredetermined distance as well as in the −X direction by a predetermineddistance based on the measurement values of encoders 170C and 170D, andsets the position of wafer stage WST1 at a position where five alignmentsystems AL1 and AL2 ₁ to AL2 ₄ can detect alignment marks arranged infive sample shot areas on wafer W almost simultaneously andindividually, as shown in FIG. 54. Then, main controller 20 detects thefive alignment mark substantially at the same time as well asindividually (refer to the star-shaped marks in FIG. 54), using the fivealignment systems AL1, and AL2 ₁ to AL2 ₄, and makes a link between thedetection results of the five alignment systems AL1, and AL2 ₁ to AL2 ₄and the measurement values of encoders 170C and 170D at the time of thedetection, and then stores them in memory (not shown). At this point,because a measurement beam from X interferometer 218 begins to irradiatereflection surface 27 c of wafer table WTB1, main controller 20 pre-setsX interferometer 218 based on measurement values of X interferometer 229(or measurement values of encoders 170C and 170D) at this point. By thisoperation, the X position and the rotation quantity (rolling amount) inthe θy direction of wafer table WTB1 can also be measured by Xinterferometer 218 hereinafter. At this point, focus mapping performedon the wafer stage WST1 side, and exposure by the step-and-scan methodof wafer W2 held on wafer table WTB2 previously described are beingcontinued.

Next, main controller 20 moves wafer stage WST in the +Y direction by apredetermined distance as well as in the +X direction by a predetermineddistance based on the measurement values of encoders 170C and 170D, andsets the position of wafer stage WST at a position where alignmentsystems AL1 and AL2 ₃ can detect alignment marks arranged in the lasttwo sample shot areas on wafer W almost simultaneously and individually,as shown in FIG. 55. Then, main controller 20 detects the two alignmentmark substantially at the same time as well as individually (refer tothe star-shaped marks in FIG. 55), using the two alignment systems AL1and AL2 ₃, and makes a link between the detection results of the twoalignment systems AL1 and AL2 ₃ and the measurement values of encoders170C and 170D at the time of the detection, and then stores them inmemory (not shown). Exposure of the step-and-scan method to wafer W2 inwafer stage WST2 is finished then. However, at this point in time, thefocus mapping on the wafer stage WST1 side previously described iscontinued. Because a measurement beam from X interferometer 226 beginsto irradiate reflection surface 27 e of wafer table WTB2 before waferstage WST2 arrives at the exposure completing position, main controller20 pre-sets X interferometer 226 based on measurement values of Xinterferometer 227 (or measurement values of encoders 170A and 170B).

Prior to completing the exposure described above, main controller 20begins periphery edge exposure (periphery scanning exposure) of wafer W1by the scanning exposure method, using periphery edge exposure unit 51(refer to FIG. 55). As it can be seen from FIG. 55, at the point whenthe periphery edge exposure begins, because 2D heads 166 ₂ and 166 ₁face moving scales 39A and 39B, main controller 20 hereinafter alsobegins measurement of positional information of wafer stare WST1 withinthe X plane, based on measurement values of 2D heads 166 ₂ and 166 ₁, ormore specifically, measurement values of encoders 170E and 170F.

Subsequently, main controller 20 moves wafer stage WST1 and wafer stageWST2 to a first scrum starting position shown in FIG. 56 whilecontinuing the per heap scanning exposure. Prior to this, the encoderused for the measurement of the positional information in the XY planeof wafer stage WST1 is changed from encoders 170C and 170D to encoders170E and 170F.

And when wafer stages WST1 and WST2 arrive at the first scrum startingposition, main controller 20 stops (turns OFF) the operation of themultipoint AF system (90 a, 90 b) (and Z heads 171 _(p) and 173 _(q))and completes the focus mapping, and then converts the surface positioninformation on each detection point of the multipoint AF system (90 a,90 b) into data which uses the surface position information by Z heads171 _(p) and 173 _(q) taken in simultaneously as a reference. Theconversion in this case is performed in a method similar to the methoddisclosed in, for example, the pamphlet of International Publication No.2007/097379.

By obtaining such converted data in advance in the manner describedabove, for example, in the case of exposure and the like, maincontroller 20 measures the wafer table WTB1 surface (a point on theareas where scales 39YB and 39A are each formed) with Z heads 74 _(i)and 76 _(j) previously described, and computes the Z position and theamount of tilt (mainly the θy rotation amount) with respect to the XYplane of wafer table WTB1. And by using the Z position and the amount oftilt (mainly the θy rotation amount) with respect to the XY plane ofwafer table WTB1 that has been computed and the conversion datapreviously described, surface position control of the wafer W uppersurface becomes possible without actually acquiring the surface positioninformation of the wafer surface.

Because EGA is also completed at the point when the focus mappingdescribed above is completed, main controller 20 uses the measurementvalues of the two encoders 170C and 170D described above whichcorrespond to the detection results of the plurality of alignment markswhich has been acquired so far and the baseline of the secondaryalignment system AL2 _(n) measured in advance to perform a statisticsoperation by the EGA method disclosed in, for example, U.S. Pat. No.4,780,617 and the like, and computes the arrays (position coordinates)of all the shot areas on wafer W1 on a coordinate system (for example,an XY coordinate system (alignment coordinate system) which uses thedetection center of primary alignment system AL1 as the origin) which isset by the measurement axes of the two encoders 170C and 170D (the twohead units 162C and 162D) described above.

As described above, in the fourth embodiment, main controller 20 makeswafer stage WST1 move back and forth in a zigzag manner while movingwafer stage WST1 in the +Y direction, and sets the position of waferstage WST1 at a plurality of points on the movement path, and on eachposition setting, detects alignment marks using at least two alignmentsystems simultaneously out of the five alignment systems AL1, and AL2 ₁to AL2 ₄. Therefore, according to the fourth embodiment, positionalinformation of alignment marks in the plurality of sample shot areas onwafer W1 can be obtained in a remarkably shorter period of time,compared with the case where a single alignment system sequentiallydetects the alignment marks. Accordingly, even if all the shot areas onwafer W1 serves as a sample shot area, measurement within a short periodof time is possible.

And, in a state where both wafer stages WST1 and WST2 are moved to thefirst scrum starting position, the stages move into a scrum state inwhich the −Y end surface (the −Y end surface of measurement section 138)of wafer table WTB2 and the +Y end surface (the +Y end surface of FD bar46) of wafer table WTB1 come into contact (or in proximity via aclearance of around 300 μm), in a state where the center line of wafertable WTB1 substantially coincides with reference axis LV₀ and thecenter line of wafer table WTB2 is shifted by a predetermined distance(a first offset amount) to the +X side of reference axis LV₀. Morespecifically, in this scrum state, by the −Y side end of measurementsection 138 configuring a part of wafer table WTB2 and the +Y end of FDbar 46 configuring a part of wafer table WTB1 being in contact (or inproximity), wafer stage WST1 and wafer stage WST2 can be in contact (orin proximity) in the Y-axis direction via FD bar 46 and measurementsection 138, in a state where a part of the surface on the +Y side ofwafer stage WST1 face a part of the surface on the −Y side of waferstage WST2.

The total length of the length of measurement section. 138 of wafertable WTB2 in the Y-axis direction and the length of FD bar 46 of wafertable WTB1 in the Y-axis direction is set to a level of length so thatwafer stage WST1 and wafer stage WST2 (or more specifically, the +Y sideend of air slider 54 of wafer stage WST1 and the −Y side end of airslider 54 of wafer stage WST2) can be kept from being in contact in astate where measurement section 138 and FD bar 46 are in contact.

Main controller 20 drives wafer stage WST1 in the +Y direction, based onmeasurement values of encoders 170E and 170F while maintaining the scrumstate, and simultaneously drives wafer stage WST2 in the +Y directionand the +X direction as shown in the outlined bold arrow shown in FIG.57, based on measurement values of interferometers 207 and 226. Duringthis movement of both wafer stages WST1 and WST2, the periphery scanningexposure is being continued.

Along with wafer stages WST1 and WST2 moving in their movementdirections while keeping the scrum state, liquid immersion area 14formed in the space between tip lens 191 and wafer table WTB2 moves fromabove wafer table WTB2 to wafer table WTB1. FIG. 57 shows a state ofboth wafer stages WST1 and WST2 just before liquid immersion area 14 ispassed to table main section 34 of wafer table WTB1 from above wafertable WTB2, via measurement section 138 of wafer table WTB2 and FD bar46 of wafer table WTB1, during such movement.

When movement of liquid immersion area 14 to the area above wafer tableWTB1 (table main section 34) is completed, and wafer stage WST1 reachesthe position (the position where measurement plate 30 is positioneddirectly under projection optical system PL) shown in FIG. 58, maincontroller 20 reduces the drive force of both water stages WST1 and WST2in +Y direction to zero. This suspends wafer stage WST1, and as shown inan outlined bold arrow in FIG. 58, drive of wafer stage WST2 in the +Xdirection begins.

Next, main controller 20 measures a projection image (aerial image) of apair of measurement marks on reticle R projected by projection opticalsystem PL, using aerial image measuring device 45A previously describedwhich includes measurement plate 30 of wafer stage WST1. An aerial imageof a pair of measurement marks is each measured by an aerial imagemeasurement operation of the slit scanning method using a pair of aerialimage measurement slit patterns SL, similar to the method disclosed in,for example, U.S. Patent Application Publication No. 2002/0041377 andthe like, and the measurement results (aerial image intensity accordingto the XY position of wafer table WTB1) are stored in memory. On themeasurement process of the aerial image of the pair of measurement markson reticle R, the position of wafer table WTB1 in the XY plane iscontrolled, based on two 2D heads 164 i and 165 j (encoders 170B and170A) that face X scales 39B and 39A.

Now, prior to starting the drive of wafer stage WST2 in the +X directionat a stage where a measurement beam from Y interferometer 207 irradiatesreflection surface 27 f of wafer table WTB2, a measurement beam from Yinterferometer 206 also begins to irradiate reflection surface 27 f.Therefore, main controller 20 pre-sets Y interferometer 205 based onmeasurement values of Y interferometer 207 right after a measurementbeam from Y interferometer 206 begins to irradiate reflection surface 27f. The position of wafer table WTB2 after the point when this preset hasbeen performed is controlled by main controller 20, based on measurementvalues of interferometers 206 and 226, as shown in FIG. 58.

Meanwhile, at a stage where wafer stages WST1 and WST2 move to theposition shown in FIG. 58 a measurement beam from X interferometer 217irradiates reflection surface 27 c of wafer table WTB1, along with ameasurement beam from Y interferometer 207 which begins to irradiatereflection surface 27 b of wafer table WTB1. Therefore, main controller20 pre-sets X interferometer 217 based on measurement values of Xinterferometer 218, along with pre-set of Y interferometer 207 based onmeasurement values of Y interferometer 209. Or, main controller 20pre-sets interferometers 207 and 217 based on measurement values ofencoders 170B and 170A. In any case, after this point in time, maincontroller 20 measures positional information of wafer table WTB1 usinginterferometers 207 and 217. As a matter of course, control of theposition of wafer table WTB1 in the XY plane is performed based onmeasurement values of encoder 170B and 170A.

And, in parallel with performing the aerial image measurement operationdescribed above, main controller 20 moves wafer stage WST2 to theposition shown in FIG. 59.

Then, when aerial image measurement operation is completed, maincontroller 20 computes the baseline of primary alignment system AL1,based on detection results on detecting fiducial mark FM on measurementplate 30 of wafer stage WST1 using primary alignment system AL1previously described and measurement results of the aerial imagedescribed above. At this point in time, the periphery edge exposure ofwafer W1 previously described is being continued.

Next, main controller 20 moves wafer stage WST1 to the exposure startingposition of wafer W1 while continuing the periphery edge exposure ofwafer W1 as shown in FIG. 60, and also begins moving wafer stage WST2 inthe −Y direction toward a right side loading position shown in FIG. 61.At the point in time when exposure of wafer W1 has begun, the peripheryedge exposure has been completed.

The exposure operation described above is performed by main controller20, based on results of wafer alignment (EGA previously described) thathas been performed beforehand and on the latest baseline and the like ofalignment systems AL1, and AL2 ₁ to AL2 ₄, by repeating a movementoperation between shots in which wafer stage WST1 is moved to a scanningstarting position (an acceleration starting position) for exposure ofeach shot area on wafer W1, and a scanning exposure operation in which apattern formed on reticle R is transferred onto each shot area by ascanning exposure method. Incidentally, the number of rows of shot areassubject to exposure on wafer W1 is even, and in the exposure describedabove, exposure is performed in a complete alternate scan, in the orderfrom a shot area located on the upper right side in FIG. 60 to a shotarea located on the lower right side.

Incidentally, during the exposure of wafer W1, the position (includingrotation in the θz direction) within the XY plane of wafer table WTB1 iscontrolled by main controller 20, based on measurement values of 2Dheads 165 _(j) and 164 _(i) (more specifically, two-dimensional encoders170A and 170B) belonging to head units 162A and 162B, respectivelyfacing movement scales 39A and 39B. Further, the position in the Z-axisdirection and θy rotation (rolling) of wafer table WTB1 which is beingexposed is controlled by main controller 20, based on measurement valuesof a pair of Z head 74 _(i) and 76 _(j) which respectively face the endson the wafer table WTB1 surface on one side and the other side (movementscale 39B, 39A) in the X-axis direction. Further, the rotation(pitching) in the θx direction of wafer table WTB1 which is beingexposed is controlled by main controller 20, based on measurement valuesof Y interferometer 207. The control (the focus leveling control ofwafer W) of the position of wafer table WTB1 in the Z-axis direction,the θy rotation, and the θx rotation during this exposure is performedbased on results of the focus mapping previously described. Further, theposition wafer table WTB1 in directions of five degrees of freedom,except for the Z-axis direction, is also measured by interferometers 207and 217.

As is obvious from FIG. 60, during the movement of wafer stage WST2toward the right side loading position, measurement beams from Xinterferometer 226 will no longer irradiate reflection surface 27 e ofwafer stage WST2, however, prior to this, measurement beams from Xinterferometer 227 begin to irradiate reflection surface 27 e whilemeasurement beams from X interferometer 226 irradiate reflection surface27 e. Therefore, main controller 20 pre-sets the measurement values of Xinterferometer 227, based on the measurement values of X interferometer226.

When wafer stage WST2 moves further in the −Y direction from theposition shown in FIG. 60, measurement beams from X interferometer 228begins to irradiate reflection surface 27 e. Therefore, whilemeasurement beams from X interferometer 227 irradiates reflectionsurface 27 e, main controller 20 pre-sets the measurement values of Xinterferometer 228 based on the measurement values of X interferometer227

When wafer stage WST2 moves further in the −Y direction, measurementbeams from X interferometer 229 begins to irradiate reflection surface27 e. Therefore, while measurement beams from X interferometer 228irradiates reflection surface 27 e, main controller 20 pre-sets themeasurement values of X interferometer 229 based on the measurementvalues of X interferometer 228.

Main controller 20 continues the exposure operation by the step-and-scanmethod to wafer W1 concurrently with driving wafer stage WST2 toward theright side loading position, while switching the X interferometer usedfor position control in the manner described above.

Then, when wafer stage WST2 reaches the right side loading positionshown in FIG. 61, main controller 20 begins Pit operation at the rightside loading position.

FIG. 62 shows a state in which Pit operation (wafer exchange performedbetween a wafer carriage mechanism (not shown) and wafer stage WST2,cooling of a wafer holder, and other preparatory operations forexposure) is performed at the right side loading position, and exposureby the step-and-scan method being concurrently performed on wafer W1held on wafer stage WST1 below projection unit PU. At this point, theposition of wafer table WTB2 is controlled by main controller 20, basedon measurement values of Y interferometer 206 and X interferometer 229.

While exposure by the step-and-scan method of wafer W1 on wafer tableWTB1 is being continued in the manner described above, main controller20 begins the drive of wafer stage WST2 in the −X direction on which Pitoperation has been completed, as shown in FIG. 63. And, wafer stage WST2is moved to a position where a reference mark FM on measurement plate 30is positioned within a field (a detection area) of primary alignmentsystem AL1, as shown in FIG. 64. During this movement, main controller20 switches the control of the position of wafer table WTB2 within theXY plane from a control based on measurement values of interferometers206 and 229 previously described to a control based on 2D heads 167 _(p)and 168 _(q) belonging to head units 162D and 162C facing moving scales39B and 39A of wafer table WTB2, or more specifically, to a controlbased on measurement values of two-dimensional encoders 170D and 170C.

Then, when wafer stage WST2 moves to the position shown in FIG. 64, maincontroller 20 performs a reset (origin reset) of Y interferometer 209, Xinterferometer 229, and two-dimensional encoders 170D and 170C, prior tostarting wafer alignment (and other preprocessing measurements) of a newwafer W2.

When the reset of interferometers 209 and 229 are completed, maincontroller 20 uses primary alignment system AL1 to detect reference markFM on measurement plate 30 of wafer stage WST2. And, main controller 20detects the position of reference mark FM with the index center ofprimary alignment system AL1 serving as a reference, and makes a linkbetween the detection results and the measurement values of encoders170C and 170D at the time of the detection, and then stores them inmemory.

Next, main controller 20 begins the scanning (scan) of wafer stage WST2in the +Y direction, and moves wafer stage WST2 to the alignment area,as shown in FIG. 65. Then, main controller 20 begins EGA previouslydescribed using encoders 170C and 170D (and interferometers 209 and 229)while measuring the position coordinates of wafer stage WST2.

FIG. 65 shows a state where alignment marks arranged in three sampleshot areas are detected almost simultaneously and individually by maincontroller 20, using primary alignment system AL1, and secondaryalignment systems AL2 ₂ and AL2 ₃ (refer to the star-shaped marks inFIG. 65). At this point, exposure by the step-and-scan method of waferW1 held on wafer table WTB1 is being continued.

After the scanning (scan) of wafer stage WST2 in the +Y direction beginsin the manner described above until wafer stage WST2 moves in the +Ydirection and detection beams of multipoint AF system (90 a, 90 b) beginto irradiate wafer W1, main controller 20 activates (turns ON) two Zheads 171 p and 173 q and multipoint AF system (90 a, 90 b) together,and begins the focus mapping previously described.

After the focus mapping has started, main controller 20 moves waferstage WST2 in the +Y direction by a predetermined distance as well as inthe +X direction by a predetermined distance based on the measurementvalues of encoders 170C and 170D, and sets the position of wafer stageWST2 at a position shown in FIG. 66. Then, main controller 20 detectsthe five alignment mark substantially at the same time as well asindividually (refer to the star-shaped marks in FIG. 66), using the fivealignment systems AL1, and AL2 ₁ to AL2 ₄, and makes a link between thedetection results of the five alignment systems AL1, and AL2 ₁ to AL2 ₄and the measurement values of encoders 170C and 170D at the time of thedetection, and then stores them in memory (not shown). At this point,focus mapping performed on the wafer stage WST2 side, and exposure bythe step-and-scan method of wafer W1 held on wafer table WTB1 previouslydescribed are being continued.

Next, main controller 20 moves wafer stage WST in the +Y direction by apredetermined distance as well as in the −X direction by a predetermineddistance based on the measurement values of encoders 170C and 170D, andsets the position of wafer stage WST at a position shown in FIG. 67.Then, main controller 20 detects the five alignment mark substantiallyat the same time as well as individually (refer to the star-shaped marksin FIG. 67), using the five alignment systems AL1, and AL2 ₁ to AL2 ₄,and makes a link between the detection results of the five alignmentsystems AL1, and AL2 ₁ to AL2 ₄ and the measurement values of encoders170C and 170D at the time of the detection, and then stores them inmemory (not shown). At this point, focus mapping performed on the waferstage WST2 side, and exposure by the step-and-scan method of wafer W1held on wafer table WTB1 previously described are being continued.

Next, main controller 20 moves wafer stage WST2 in the +Y direction by apredetermined distance as well as in the +X direction by a predetermineddistance based on the measurement values of encoders 170C and 170D, andsets the position of wafer stage WST2 at a position shown in FIG. 68.Then, main controller 20 detects the five alignment mark substantiallyat the same time as well as individually (refer to the star-shaped marksin FIG. 68), using the five alignment systems AL1, and AL2 ₁ to AL2 ₄,and makes a link between the detection results of the five alignmentsystems AL1, and AL2 ₁ to AL2 ₄ and the measurement values of encoders170C and 170D at the time of the detection, and then stores them inmemory (not shown). At this point, because a measurement beam from Xinterferometer 228 begins to irradiate reflection surface 27 e of wafertable WTB2, main controller 20 pre-sets X interferometer 228 based onmeasurement values of X interferometer 229 at this point. By thisoperation, the X position and the rotation quantity (rolling amount) inthe θy direction of wafer table WTB2 can also be measured by Xinterferometer 228 hereinafter. At this point, focus mapping performedon the wafer stage WST2 side, and exposure by the step-and-scan methodof wafer W1 held on wafer table WTB1 previously described are beingcontinued.

Next, main controller 20 moves wafer stage WST2 in the +Y direction by apredetermined distance as well as in the −X direction by a predetermineddistance based on the measurement values of encoders 170C and 170D, andsets the position of wafer stage WST2 at a position shown in FIG. 69.Then, main controller 20 detects the two alignment mark substantially atthe same time as well as individually (refer to the star-shaped marks inFIG. 69), using the two alignment systems AL1 and AL2 ₂, and makes alink between the detection results of the two alignment systems AL1 andAL2 ₂ and the measurement values of encoders 170C and 170D at the timeof the detection, and then stores them in memory (not shown). At thispoint, the exposure by the step-and-scan method of wafer W1 on waferstage WST1 is completed. However, at this point in time, the focusmapping on the wafer stage WST2 side previously described is continued.Because a measurement beam from X interferometer 226 begins to irradiatereflection surface 27 a of wafer table WTB1 before wafer stage WST1arrives at the exposure completing position, main controller 20 pre-setsX interferometer 226 based on measurement values of X interferometer 217(or measurement values of encoders 170A and 170B).

Prior to completing the exposure described above, main controller 20begins periphery scanning exposure of wafer W2 (refer to FIG. 69). As itcan be seen from FIG. 69, at the point when the periphery edge exposurebegins, because 2D heads 166 ₂ and 166 ₁ face moving scales 39A and 39B,main controller 20 hereinafter also begins measurement of positionalinformation of wafer stage WST2 within the XY plane, based onmeasurement values of 2D heads 166 ₂ and 166 ₁, or more specifically,measurement values of encoders 170E and 1701F.

Subsequently, main controller 20 moves wafer stage WST1 and wafer stageWST2 to a second scrum starting position shown in FIG. 70 whilecontinuing the periphery scanning exposure. Prior to this, the encoderused for the measurement of the positional information in the XY planeof wafer stage WST2 is changed from encoders 170C and 170D to encoders170E and 170F.

And when wafer stages WST1 and WST2 arrive at the second scrum startingposition, main controller 20 completes the focus mapping, and thenconverts the surface position information on each detection point of themultipoint AF system (90 a, 90 b) into data which uses the surfaceposition information by Z heads 171 _(p) and 173 _(q) taken insimultaneously as a reference in a similar manner as previouslydescribed.

Because EGA is also completed at the point when the focus mappingdescribed above is completed, main controller 20 uses the measurementvalues of the two encoders 170C and 170D described above whichcorrespond to the detection results of the plurality of alignment markswhich has been acquired so far and the baseline of the secondaryalignment system AL2, measured in advance to perform a statisticsoperation by the EGA method, and computes the arrays (positioncoordinates) of all the shot areas on wafer W1 on a coordinate system(for example, an XY coordinate system (alignment coordinate system)which uses the detection center of primary alignment system AL1 as theorigin) which is set by the measurement axes of the two encoders (thetwo head units) described above.

In this case, in a state where both wafer stages WST1 and WST2 are movedto the second scrum starting position, the stages move into a scrumstate in which the −Y end surface (the −Y end surface of measurementsection 138) of wafer table WTB2 and the +Y end surface (the +Y endsurface of FD bar 46) of wafer table WTB1 come into contact (or inproximity via a clearance of around 300 μm), in a state where the centerline of wafer table WTB2 substantially coincides with reference axis LV₀and the center line of wafer table WTB1 is shifted by a predetermineddistance (a second offset amount) to the −X side of reference axis LV₀.More specifically, in this scrum state, by the −Y side end ofmeasurement section 138 configuring a part of wafer table WTB1 and the+Y end of PD bar 46 configuring a part of wafer table WTB2 being incontact (or in proximity), wafer stage WST2 and wafer stage WST1 can bein contact (or in proximity) in the Y-axis direction via FD bar 46 andmeasurement section 138, in a state where a part of the surface on the+Y side of wafer stage WST2 face a part of the surface on the −Y side ofwafer stage WST1. In this case, the second offset amount is set to adistance the same as the first offset amount previously described.

The total length of the length of measurement section 138 of wafer tableWTB1 in the Y-axis direction and the length of FD bar 46 of wafer tableWTB2 in the Y-axis direction is set to a level of length so that waferstage WST2 and wafer stage WST1 (or more specifically, the +Y side endof air slider 54 of wafer stage WST2 and the −Y side end of air slider54 of wafer stage WST1) can be kept from being in contact in a statewhere measurement section 138 and FD bar 46 are in contact.

Main controller 20 drives wafer stage WST2 in the +Y direction, based onmeasurement values of encoders 170E and 170F while maintaining the scrumstate, and simultaneously drives wafer stage WST1 in the +Y directionand the −X direction as shown in the outlined bold arrow shown in FIG.71, based on measurement values of interferometers 207 and 226. Duringthis movement of both wafer stages WST1 and WST2, the periphery scanningexposure is being continued.

Along with wafer stages WST1 and WST2 moving in their movementdirections while keeping the scrum state, liquid immersion area 14formed in the space between tip lens 191 and wafer table WTB2 moves fromabove wafer table WTB1 to wafer table WTB2. FIG. 71 shows a state ofboth wafer stages WST1 and WST2 just before liquid immersion area 14 ispassed to table main section 34 of wafer table WTB2 from above wafertable WTB1, via measurement section 138 of wafer table WTB1 and FD bar46 of wafer table WTB2, during such movement.

When movement of liquid immersion area 14 to the area above wafer tableWTB2 (table main section 34) is completed, and wafer stage WST2 reachesthe position (the position where measurement plate 30 is positioneddirectly under projection optical system PL) shown in FIG. 72, maincontroller 20 reduces the drive force of both wafer stages WST1 and WST2in +Y direction to zero. This suspends wafer stage WST2, and as shown inan outlined bold arrow in FIG. 72, drive of wafer stage WST1 in the −Xdirection begins.

Next, main controller 20 measures a projection image (aerial image) of apair of measurement marks on reticle R projected by projection opticalsystem PL, using aerial image measuring device 45B previously describedwhich includes measurement plate 30 of wafer stage WST2. On themeasurement process of the aerial image, the position of wafer tableWTB2 in the XY plane is controlled, based on two 2D heads 165 _(j) and164 _(i) (encoders 170B and 170A) that face X scales 39A and 39B.

Now, prior to starting the drive of wafer stage WST1 in the −X directionat a stage where a measurement beam from Y interferometer 207 irradiatesreflection surface 27 b of wafer table WTB1, a measurement beam from Yinterferometer 208 also begins to irradiate reflection surface 27 b.Therefore, main controller 20 pre-sets Y interferometer 208 based onmeasurement values of Y interferometer 207, right after a measurementbeam from Y interferometer 208 begins to irradiate reflection surface 27b. The position of wafer table WTB1 after the point when this preset hasbeen performed, is controlled by main controller 20, based onmeasurement values of interferometers 208 and 226, as shown in FIG. 72.

Meanwhile, at a stage where wafer stages WST1 and WST2 move to theposition shown in FIG. 72, a measurement beam from X interferometer 227irradiates reflection surface 27 e of wafer table WTB2, along with ameasurement beam from Y interferometer 207 which begins to irradiatereflection surface 27 f of wafer table WTB1. Therefore, main controller20 pre-sets X interferometer 227 based on measurement values of Xinterferometer 228, along with pre-set of Y interferometer 207 based onmeasurement values of Y interferometer 209. Or, main controller 20pre-sets interferometers 207 and 227 based on measurement values ofencoders 170B and 170A. In any case, after this point in time, maincontroller 20 measures positional information of wafer table WTB1 usinginterferometers 207 and 227. As a matter of course, control of theposition of wafer table WTB2 in the XY plane is performed based onmeasurement values of encoder 170B and 170A.

And, in parallel with performing the aerial image measurement operationdescribed above, main controller 20 moves wafer stage WST1 to theposition shown in FIG. 73.

Then, when aerial image measurement is completed, main controller 20computes the baseline of primary alignment system AL1, based ondetection results on detecting fiducial mark FM on measurement plate 30of wafer stage WST2 using primary alignment system AL1 previouslydescribed and measurement results of the aerial image described above.At this point in time, the periphery edge exposure of wafer W2previously described is being continued.

Next, main controller 20 moves wafer stage WST2 to the exposure startingposition of wafer W2 while continuing the periphery edge exposure ofwafer W2 as shown in FIG. 73, and also begins moving wafer stage WST1 inthe −Y direction toward a left side loading position shown in FIG. 75.

Then, main controller 20 begins exposure of wafer W2 in a proceduresimilar to the one previously described. At the point in time whenexposure of wafer W2 has begun, the periphery edge exposure has beencompleted.

As is obvious from FIG. 74, during the movement of wafer stage WST1toward the left side loading position, measurement beams from Xinterferometer 226 will no longer irradiate reflection surface 27 a ofwafer stage WST1, however, prior to this, measurement beams from Xinterferometer 217 begin to irradiate reflection surface 27 c whilemeasurement beams from X interferometer 226 irradiate reflection surface27 a. Therefore, the measurement values of X interferometer 217 arepre-set, based on the measurement values of X interferometer 226.

When wafer stage WST1 moves further in the −Y direction from theposition shown in FIG. 74, measurement beams from X interferometer 218begins to irradiate reflection surface 27 c. Therefore, whilemeasurement beams from X interferometer 217 irradiates reflectionsurface 27 c, main controller 20 pre-sets the measurement values of Xinterferometer 218 based on the measurement values of X interferometer217.

When wafer stage WST1 moves further in the −Y direction, measurementbeams from X interferometer 229 begins to irradiate reflection surface27 a. Therefore, while measurement beams from X interferometer 218irradiates reflection surface 27 c, main controller 20 pre-sets themeasurement values of X interferometer 229 based on the measurementvalues of X interferometer 228.

Main controller 20 continues the exposure operation by the step-and-scanmethod to wafer W2 concurrently with driving wafer stage WST1 toward theleft side loading position, while switching the X interferometer usedfor position control in the manner described above.

Then, when wafer stage WST1 reaches the left side loading position shownin FIG. 75, main controller 20 begins Pit operation at the left sideloading position.

FIG. 76 shows a state in which wafer exchange between a wafer carriagemechanism (not shown) and wafer stage WST1 is performed as a part of Pitoperation at the left side loading position, and exposure by thestep-and-scan method is being concurrently performed on wafer W2 held onwafer stage WST2 below projection unit PU.

Hereinafter, main controller 20 repeatedly executes the paralleloperation using wafer stage WST1 and WST2 described above.

As discussed in detail so far, according to exposure apparatus 1000 ofthe fourth embodiment, in parallel with the exposure of the wafer (W1 orW2) held by one of wafer stages WST1 and WST2 performed by maincontroller 20, the other stage of wafer stages WST1 and WST2 is moved inthe X-axis direction while also being moved in the Y-axis direction, anda plurality of different alignment marks on the wafer held by the otherwafer stage is positioned sequentially within the detection area (aplurality of detection areas) of alignment systems AL1, and AL2 ₁ to AL2₄, and positional information of the alignment marks which are locatedwithin the detection areas of alignment system AL1, and AL2 ₁ to AL2 ₄is sequentially detected. Accordingly, while the other wafer stage movesin the Y-axis direction from a position. In the vicinity of thedetection areas (for example, a position in the vicinity of the positionwhere exchange of the wafer which is held by the wafer stage isperformed) of alignment systems AL1, and AL2 ₁ to AL2 ₄ to the exposureposition (directly below projection unit PU, exposure area IA)concurrently with the exposure of the wafer held by the one wafer stageWST, it becomes possible to detect the plurality of alignment marks, forexample, all of the alignment marks on the wafer held by the otherstage. As a consequence, it becomes possible to achieve improvement ofthe throughput as well as improvement of the overlay accuracy. Further,main controller 20 controls periphery edge exposure unit 51, and anenergy beam which has almost the same wavelength as illumination lightIL is irradiated on a part of the shot areas in the periphery section ofthe wafer held by the other wafer stage passing below periphery edgeexposure unit 51, while the stage moves toward the exposure position.Accordingly, improvement of the yield can be achieved without decreasingthe throughput.

Further, in exposure apparatus 1000 of the fourth embodiment, maincontroller performs Pit operation, or more specifically, wafer exchangebetween the wafer transport mechanism (not shown) and the other waferstage, cooling of the wafer holder, and other preparatory operations forexposure at the other loading position of wafer stages WST1 and WST2,concurrently with the exposure of the wafer (W1 or W2) held by one ofwafer stages WST1 and WST2. Accordingly, operations such as the coolingof the wafer holder can be performed without decreasing the throughput.

Further, according to the fourth embodiment, main controller 20 controlsplanar motor 151 which drives wafer stages WST1 and WST2 within the XYplane, as well as move wafer stage WST1 to the left side loadingposition where exchange of wafer W1 on wafer stage WST1 is performedalong a first return path located on one side (−X side) in the X-axisdirection of the exposure position of wafer stage WST1 when exposure ofwafer W1 held by wafer stage WST1 has been completed, and also movewafer stage WST2 to the right side loading position where exchange ofwafer W2 on wafer stage WST2 is performed along a second return pathlocated on the other side (+X side) in the X-axis direction of theexposure position of wafer stage WST2 when exposure of wafer W2 held bywafer stage WST2 has been completed. Accordingly, attaching a cable forwiring/piping to wafer stage WST1 from one side in the +X direction,while attaching a cable for wiring/piping to wafer stage WST2 from theother side in the +X direction can keep the cables from being tangled,as well as keep the length as short as possible.

Further, in exposure apparatus 1000 of the fourth embodiment, whenexposure of wafer W1 is completed, main controller 20 drives wafer stageWST2 in the +Y direction as well as drive wafer stage WST1 in the +Ydirection and the −X direction while maintaining a scrum state in whichmeasurement section 138 of wafer stage WST1 and FD bar 46 of wafer stageWST2 are in proximity or in contact, and delivers liquid immersion area14 from the area over wafer stage WST1 to wafer stage WST2. As soon asliquid immersion area 14 has been delivered, main controller reduces thedrive force of both wafer stages WST1 and WST2 in the +Y direction tozero at a position where measurement plate 30 of wafer stage WST2 ispositioned directly under projection optical system PL. This suspendswafer stage WST2, and as shown in an outlined bold arrow in FIG. 72,wafer stage WST1 begins to move in the −X direction and moves toward theleft loading position along the first return path described above. Inorder to efficiently begin the movement of wafer stage WST1 along thefirst return path, at the second scrum starting position, the scrumstate of both wafer stages WST1 and WST2 is to begin in a state wherethe center line of wafer table WTB2 approximately coincides withreference axis LV₀, and the center line of wafer table WTB1 is shiftedby a predetermined distance (the second offset amount) to the −X sidefrom reference axis LV₀.

Meanwhile, when exposure of wafer W2 is completed, main controller 20drives wafer stage WST1 in the +Y direction as well as drive wafer stageWST2 in the +Y direction and the +X direction while maintaining a scrumstate in which measurement section 138 of wafer stage WST2 and FD bar 46of wafer stage WST1 are in proximity or in contact in a similar manneras is previously described, and delivers liquid immersion area 14 fromthe area over wafer stage WST2 to wafer stage WST1. As soon as liquidimmersion area 14 has been delivered, main controller reduces the driveforce of both wafer stages WST1 and WST2 in the +Y direction to zero ata position where measurement plate 30 of wafer stage WST1 is positioneddirectly under projection optical system PL. This suspends wafer stageWST1, and as shown in an outlined bold arrow in FIG. 58, wafer stageWST1 begins to move in the +X direction and moves toward the rightloading position along the second return path described above. In orderto efficiently begin the movement of wafer stage WST2 along the secondreturn path, at the first scrum starting position, the scrum state ofboth wafer stages WST1 and WST2 is to begin in a state where the centerline of wafer table WTB1 approximately coincides with reference axisLV₀, and the center line of wafer table WTB2 is shifted by apredetermined distance (the first offset amount) to the +X side fromreference axis LV₀.

As it can be seen from the description above, in exposure apparatus 1000of the fourth embodiment, the offset amount of wafer stage WST1 and WST2in the X-axis direction at the time when the scrum begins is decided sothat the movement of one of the wafer stages along the return pathtoward the loading position to which the one wafer stage corresponds canbe started most efficiently after exposure of the wafer on the one waferstage has been completed, or more specifically, so that the movementpath of the one wafer stage is the shortest, and also has the shortesttime distance.

Incidentally, in the fourth embodiment described above, while the offsetamount of wafer stage WST1 and WST2 in the X-axis direction at the timewhen the scrum begins was decided so that the movement of the waferstage holding the wafer which has been exposed along the return pathtoward the loading position to which the one water stage corresponds canbe started most efficiently, instead of this, or along with this, theoffset amount of wafer stage WST1 and WST2 in the X-axis direction atthe time when the scrum begins can be decided so that exposure of thewafer subject to the next exposure can be started most efficiently.

The scrum of both wafer stages which makes it possible to mostefficiently start the movement of one of the wafer stages along thereturn path toward the loading position to which the one wafer stagecorresponds after exposure of the wafer on the one wafer stage has beencompleted, or the scrum of both wafer stages which allows the exposureof the wafer subject to the next exposure to be performed in the mostefficient manner can be referred to as the most efficient scrum.

Further, in the fourth embodiment described above, while the case hasbeen described where a Y direction scrum in which both wafer stages WST1and WST2 are in contact or in proximity in the Y-direction was employedto deliver liquid immersion area 14 between both wafer stages WST1 andWST2, besides this, an X direction scrum in which both wafer stages WST1and WST2 are in contact or in proximity in the X-direction can heemployed to deliver liquid immersion area 14 between both wafer stagesWST1 and WST2. In this case, an offset can be applied to both waferstages WST1 and WST2 in the Y-axis direction at the beginning of thescrum.

Further, even in the case the Y direction scrum is employed as in thefourth embodiment described above, a case can be considered where a partof the mechanism section protrudes from the side surface of wafer stagesWST1 and WST2 in the Y-axis direction. In such cases, it is desirable toset the length of the measurement section and the dimension of the FDbar in the Y-axis direction, and/or the offset amount at the time of thescrum to a level so that such a protruding section does not come intocontact with a part of the other wafer stage.

Incidentally, in the fourth embodiment described above, while the casehas been described where a fixed protruding section was arranged inwafer stages WST1 and WST2 in the measurement section and table mainsection 34 such as the FD bar and the like, in the case the main purposeof the protruding section is to deliver the liquid immersion areabetween both wafer stages WST1 and WST2, the protruding section can bemovable. In this case, for example, the protruding sections can be in asubstantially horizontal state only when both wafer stages WST1 and WST2are in a serum state, and at the time besides the scrum, or morespecifically, when the protruding sections are not used, the protrudingsections can be folded. Further, in the fourth embodiment, while themeasurement section and the FD bar were used also as a protrudingsection, besides this, a fixed protruding section can be arrangedexclusively in wafer stages WST1 and WST2.

Incidentally, in the fourth embodiment described above, the case hasbeen described where after the exposure has been completed, wafer stageWST1 is moved to the first exchange position where exchange of wafer W1on wafer stage WST1 is performed along the first return path located onthe −X side of wafer stage WST1 and wafer stage WST2 is moved to thesecond exchange position where exchange of wafer W2 on wafer stage WST2is performed along the second return path located on the +X side ofwafer stage WST2, after switching between a proximity state (a scrumstate) in which both wafer stages WST1 and WST2 are made to be inproximity in the Y-axis direction by a predetermined distance or lessand a separation state (a scrum release state) in which both waferstages WST1 and WST2 are separated, in order to deliver liquid immersionarea 14 from one of the wafer stages to the other wafer stage. Morespecifically, the case where first exchange position and the secondexchange position are separate was described. However, as well as this,the second exchange position can be the same as the first exchangeposition. In such a case, a configuration can be employed where afterexposure has been completed on the wafer held by one of the wafer stagesat the exposure position, main controller 20 makes both stages WST1 andWST2 perform the switching between the proximity state (scrum state) inwhich both wafer stages WST1 and WST2 are made to be in proximity in theY-axis direction by a predetermined distance or less and the separationstate (scrum release state) in which both wafer stages WST1 and WST2 areseparated in order to deliver liquid immersion area 14 from one of thewafer stages to the other wafer stage, and also controls the planarmotor so that the one wafer stage separated from the other wafer stageis moved to the exchange position where exchange of the wafer on bothstages WST1 and WST2 is performed along a return path positioned on oneside of the exposure position in the X-axis direction. In such a case,the movement range of both wafer stages in the X-axis direction can beset narrower when compared with the case where one wafer stage is movedto the exchange position along a return path positioned on one side ofthe exposure position in the X-axis direction and the other wafer stageis moved to the exchange position along a return path positioned on theother side of the exposure position in the X-axis direction.

Further, in the fourth embodiment above, wafer stages WST1 and WST2 weredriven independently along the XY plane by a planar motor, with themovement path of wafer stages WST1 and WST2 previously described givenas a premise. However, the planar motor does not necessarily have to beused, and a linear motor may also be used depending on the movementpath.

Incidentally, in the fourth embodiment, periphery edge exposure unit 51does not necessarily have to be arranged. Even in such a case, thevarious kinds of effects described above can be obtained.

Incidentally, in the fourth embodiment above, in parallel with maincontroller 20 performing exposure on the wafer (W1 or W2) held by one ofwafer stages WST1 and WST2, only a plurality of different alignmentmarks on the wafer held by the other wafer stage has to be detected byalignment systems AL1 and AL2 ₁ to AL2 ₄ and the positional informationmeasured, while the other wafer stage of wafer stages WST1 and WST2 isdriven in the Y-axis direction. More specifically, the movement pathfrom the exposure position to the wafer exchange position can be thesame for wafer stages WST1 and WST2. Further, as for the other waferstage of wafer stages WST1 and WST2 described above, only a plurality ofdifferent alignment marks on the wafer held by the other wafer stage hasto be detected while being moved in the Y-axis direction, without beingmoved in the X-axis direction. Further, periphery edge exposure does nothave to be performed while the other wafer stage is moving in the Y-axisdirection as described above. Further, wafer stages WST1 and WST2 do notnecessarily have to be driven by a planar motor.

Meanwhile, in the fourth embodiment described above, main controller 20only has to control planar motor 151 which drives wafer stages WST1 andWST2 within the XY plane, as well as move wafer stage WST1 to the leftside loading position where exchange of wafer W1 on wafer stage WST1 isperformed along a first return path located on one side (−X side) in theX-axis direction of the exposure position of wafer stage WST1 whenexposure of wafer W1 held by wafer stage WST1 has been completed, andalso move wafer stage WST2 to the right side loading position whereexchange of wafer W2 on wafer stage WST2 is performed along a secondreturn path located on the other side (+X side) in the X-axis directionof the exposure position of wafer stage WST2 when exposure of wafer W2held by wafer stage WST2 has been completed. More specifically,measurement of the positional information of a plurality of differentalignment marks on the wafer held by the other wafer stage does not haveto be performed in parallel with the exposure performed on the waferheld by one of wafer stages WST1 and WST2, not to mention the peripheryedge exposure of the wafer held by the other wafer stage of wafer stagesWST1 and WST2. Further, the planar motor can be a moving coil typemotor.

Further, in the fourth embodiment above, while the case has beendescribed where measurement system 200 includes interferometer systems118 and encoder system 150, as well as this, the measurement system caninclude only one of interferometer system 118 and encoder system 150.Especially in the case when the measurement system includes only anencoder system, the encoder system does not necessarily have to be atwo-dimensional encoder including a 2D head.

Incidentally, in each of the first and fourth embodiments describedabove, while the examples were described where periphery edge exposureunit 51 was configured using a micromirror array, besides such examples,the configuration of periphery edge exposure unit 51 is not an issue inparticular, as long as exposure of an arbitrary position (area) on thewafer can be performed freely, using a light having almost the samewavelength as illumination light IL. For example, the periphery edgeexposure unit can be configured using a spatial light modulator otherthan the micromirror array. Further, the periphery edge exposure unitcan be configured using a reticle and projection optical system PL.Further, in the periphery edge exposure, a pattern which is the same asthe one transferred on a shot area in normal exposure can betransferred, or a different pattern can be transferred. In this case,for example, the transfer pattern density and the like is preferably thesame, or not too different. However, the line width can be coarse.

Incidentally, placements, configurations and the like of each of themeasurement devices such as the encoder head, Z head, interferometer andthe like described in the first to fourth embodiments above are mereexamples, and it is a matter of course that the present invention is notlimited to this. For example, the number of heads that the head unitsare equipped with is not limited to the ones described above, and thenumbers are not an issue as long as the heads are arranged on both theouter sides of the plurality of mark detection systems (in each of theembodiments above, alignment systems AL1, AL2 ₁ to AL2 ₄). The importantthing is, on detecting specific alignment marks on wafer w with each ofthe plurality of mark detection systems, the heads facing the pair ofscales should be at least one each. Further, in each of the embodimentsabove, while the case has been described where the Y position of the twoheads which were located innermost among the plurality of heads arrangedon both of the outer sides of the plurality of mark detection systemswere different from the other heads, the Y position of any other headscan also be different. The important thing is, the Y position of anarbitrary head should be different from the Y position of other heads,in correspondence with the empty space. Or, in the case there is enoughempty space on both of the outer sides of the plurality of markdetection systems, all the heads can be placed at the same Y position.

Further, the number of mark detection systems (alignment systems) is notlimited to five, and while it is desirable that two or more markdetection systems whose position of the detection area is different in asecond direction (the X-axis direction in each of the embodimentsabove), the number is not an issue in particular.

Further, in each of the embodiments above, in the case when only anencoder system is arranged without arranging an interferometer system,the Z head can also be made to measure the positional information of thewafer table in the θx direction.

Further, in each of the first, second, and fourth embodiments, anencoder system which has an encoder head arranged on a wafer table aswell as a scale on which a one-dimensional or a two-dimensional grating(for example, a diffraction grating) is formed that is placed above thewafer table facing the encoder head can be used, as in the thirdembodiment or as is disclosed in, for example, the U.S. PatentApplication Publication No. 2006/0227309 and the like. In this case, theZ heads can also be placed on the wafer table, and the surface of thescale described above can be used also as the reflection surface onwhich the measurement beams from the Z heads are irradiated. Further, ahead whose measurement direction is also in the Z-axis direction inaddition to the X-axis direction and/or the Y-axis direction that alsohas the function of, so to speak, an encoder head and a Z head, can beused. In this case, the Z heads will, not be necessary. Incidentally, ineach of the embodiments above, while the lower surface of nozzle unit 32and the lower end surface or the tip optical element of projectionoptical system PL were on a substantially flush surface, as well asthis, for example, the lower surface of nozzle unit 32 can be placednearer to the image plane (more specifically, to the wafer) ofprojection optical system PL than the outgoing surface of the tipoptical element. That is, the configuration of local liquid immersionunit 8 is not limited to the configuration described above, and theconfigurations can be used, which are described in, for example, EPPatent Application Publication No. 1420298, the pamphlet ofInternational Publication No. 2004/055803, the pamphlet of InternationalPublication No. 2004/057590, the pamphlet of international PublicationNo. 2005/029559 (the corresponding U.S. Patent application PublicationNo. 2006/0231206), the pamphlet of International Publication No.2004/086468 (the corresponding U.S. Patent Application Publication No.2005/0280791), Kokai (Japanese Unexamined Patent ApplicationPublication) No. 2004-289126 (the corresponding U.S. Pat. No.6,952,253), and the like. Further, as disclosed in the pamphlet ofInternational Publication No. 2004/019128 (the corresponding U.S. PatentApplication Publication No. 2005/0248856 description), the optical pathon the object plane side of the tip optical element may also be filledwith liquid, in addition to the optical path on the image plane side ofthe tip optical element. Furthermore, a thin film that is lyophilicand/or has dissolution preventing function may also be formed on thepartial surface (including at least a contact surface with liquid) orthe entire surface of the tip optical element. Incidentally, quartz hasa high affinity for liquid, and also needs no dissolution preventingfilm, while in the case of fluorite, at least a dissolution preventingfilm is preferably formed.

Incidentally, in each of the embodiments above, pure water (water) wasused as the liquid, however, it is a matter of course that the presentinvention is not limited to this. As the liquid, a chemically stableliquid that has high transmittance to illumination light IL and is safeto use, such as a fluorine-containing inert liquid can be used. As thefluorine-containing inert liquid, for example, Fluorinert (the brandname of 3M United States) can be used. The fluorine-containing inertliquid is also excellent from the point of cooling effect. Further, asthe liquid, liquid which has a refractive index higher than pure water(a refractive index is around 1.44), for example, liquid having arefractive index equal to or higher than 1.5 can be used. As this typeof liquid, for example, a predetermined liquid having C—H binding or O—Hbinding such as isopropanol having a refractive index of about 1.50,glycerol (glycerin) having a refractive index of about 1.61, apredetermined liquid (organic solvent) such as hexane, heptane ordecane, or decalin (decahydronaphthalene) having a refractive index ofabout 1.60, or the like can be cited. Alternatively, a liquid obtainedby mixing arbitrary two or more of these liquids may be used, or aliquid obtained by adding (mixing) at least one of these liquids to(with) pure water may be used. Alternatively as the liquid, a liquidobtained by adding (mixing) base or acid such as H⁺, Cs⁺, K⁺, Cl⁻, SO₄²⁻, or PO₄ ²⁻ to (with) pure water can be used. Moreover, a liquidobtained by adding (mixing) particles of Al oxide or the like to (with)pure water can be used. These liquids can transmit ArF excimer laserlight. Further, as the liquid, which has a small absorption coefficientof light, is less temperature-dependent, and is stable to a projectionoptical system (tip optical member) and/or a photosensitive agent (or aprotection film (top coat film), an antireflection film, or the like)coated on the surface of a wafer, is preferable. Further, in the case anF₂ laser is used as the light source, fomblin oil can be selected.Further, as the liquid, a liquid having a higher refractive index toillumination light IL than that of pure water, for example, a refractiveindex of around 1.6 to 1.8 may be used. As the liquid, supercriticalfluid can also be used. Further, the tip optical element of projectionoptical system PL may be formed by quartz (silica), or single-crystalmaterials of fluoride compound such as calcium fluoride (fluorite),barium fluoride, strontium fluoride, lithium fluoride, and sodiumfluoride, or may be formed by materials having a higher refractive indexthan that of quartz or fluorite (e.g. equal to or higher than 1.6). Asthe materials having a refractive index equal to or higher than 1.6, forexample, sapphire, germanium dioxide, or the like disclosed in thepamphlet of International Publication No. 2005/059617, or kaliumchloride (having a refractive index of about 1.75) or the like disclosedin the pamphlet of International Publication No. 2005/059618 can beused.

Further, in each of the embodiments above, withdrawn liquid may bereused, it is desirable that this case arranges a filter removingimpurities from withdrawn liquid in liquid recovery device or a recoverypipe.

Further, in each of the embodiments above, the case has been described,where the exposure apparatus is a liquid immersion type exposureapparatus. However, the present invention is not limited to this, butcan also be employed in a dry type exposure apparatus that performsexposure of wafer W without liquid (water).

Further, in each of the embodiments above, the case has been describedwhere the present invention is applied to a scanning exposure apparatusby a step-and-scan method or the like. However, the present invention isnot limited to this, but may also be applied to a static exposureapparatus such as a stepper. Further, the present invention can also beapplied to a projection exposure apparatus by a step-and-stitch methodthat synthesizes a shot area and a shot area, an exposure apparatus by aproximity method, a mirror projection aligner, or the like.

Further, the magnification of the projection optical system in theexposure apparatus in each of the embodiments above is not only areduction system, but also may be either an equal magnifying system or amagnifying system, and projection optical system PL is not only adioptric system, but also may be either a catoptric system or acatadioptric system, and in addition, the projected image may be eitheran inverted image or an upright image. Moreover, exposure area IA towhich illumination light IL is irradiated via projection optical systemPL is an on-axis area that includes optical axis AX within the field ofprojection optical system PL. However, for example, as is disclosed inthe pamphlet of International Publication No. 2004/107011, exposure areaIA may also be an off-axis area that does not include optical axis AX,similar to a so-called inline type catadioptric system, in part of whichan optical system (catoptric system or catadioptric system) that hasplural reflection surfaces and forms an intermediate image at least onceis arranged, and which has a single optical axis. Further, theillumination area and exposure area described above are to have arectangular shape. However, the shape is not limited to rectangular, andcan also be circular arc, trapezoidal, parallelogram or the like.

Incidentally, the light source of the exposure apparatus in each of theembodiments above is not limited to the ArF excimer laser, but a pulselaser light source such as a KrF excimer laser (output wavelength: 248nm), an F₂ laser (output wavelength: 157 nm), an Ar₂ laser (outputwavelength: 126 nm) or a Kr₂ laser (output wavelength: 146 nm), or anextra-high pressure mercury lamp that generates an emission line such asa g-line (wavelength: 436 nm) or an i-line (wavelength: 365 nm) can alsobe used. Further, a harmonic wave generating unit of a YAG laser or thelike can also be used. Besides the sources above, as is disclosed in,for example, the pamphlet of International Publication No. 1999/46835(the corresponding U.S. Pat. No. 7,023,610 description), a harmonicwave, which is obtained by amplifying a single-wavelength laser beam inthe infrared or visible range emitted by a DFB semiconductor laser orfiber laser as vacuum ultraviolet light, with a fiber amplifier dopedwith, for example, erbium (or both erbium and ytteribium), and byconverting the wavelength into ultraviolet light using a nonlinearoptical crystal, can also be used.

Further, in the embodiment above, illumination light IL of the exposureapparatus is not limited to the light having a wavelength equal to ormore than 100 nm, and it is needless to say that the light having awavelength less than 100 nm can be used. For example, the presentinvention can also be suitably applied to an EUV exposure apparatus thatuses a total reflection reduction optical system designed under awavelength range of 5 to 15 nm, such as for example, 13.5 nm, and areflective mask. Besides such an apparatus, the present invention canalso be applied to an exposure apparatus that uses charged particlebeams such as an electron beam or an ion beam.

Further, in each of the embodiments above, a transmissive type mask(reticle) is used, which is a transmissive substrate on which apredetermined light shielding pattern (or a phase pattern or a lightattenuation pattern) is formed. Instead of this reticle, however, as isdisclosed in, for example, U.S. Pat. No. 6,778,257 description, anelectron mask (which is also called a variable shaped mask, an activemask or an image generator, and includes, for example, a DMD (DigitalMicromirror Device) that is a type of a non-emission type image displaydevice (spatial light modulator) or the like) on which alight-transmitting pattern, a reflection pattern, or an emission patternis formed according to electronic data of the pattern that is to beexposed can also be used.

Further, as is disclosed in, for example, the pamphlet of InternationalPublication No. 2001/035168, the present invention can also be appliedto an exposure apparatus (lithography system) that forms line-and-spacepatterns on a wafer by forming interference fringes on the wafer.

Moreover, the present invention can also be applied to an exposureapparatus that synthesizes two reticle patterns via a projection opticalsystem and almost simultaneously performs double exposure of one shotarea by one scanning exposure, as is disclosed in, for example, Kohyo(published Japanese translation of international Publication for PatentApplication) No. 2004-519850 bulletin (the corresponding U.S. Pat. No.6,611,316).

Further, an apparatus that forms a pattern on an object is not limitedto the exposure apparatus (lithography system) described above, and forexample, the present invention can also be applied to an apparatus thatforms a pattern on an object by an ink-jet method.

Incidentally, an object on which a pattern is to be formed (an objectsubject to exposure to which an energy beam is irradiated) in each ofthe embodiments above is not limited to a wafer, but may be otherobjects such as a glass plate, a ceramic substrate, a film member, or amask blank.

The use of the exposure apparatus is riot limited only to the exposureapparatus for manufacturing semiconductor devices, but the presentinvention can also be widely applied, for example, to an exposureapparatus for transferring a liquid crystal display device pattern ontoa rectangular glass plate, and an exposure apparatus for producingorganic ELs thin-film magnetic heads, imaging devices (such as CCDs)micromachines, DNA chips, and the like. Further, the present inventioncan be applied not only to an exposure apparatus for producingmicrodevices such as semiconductor devices, but can also be applied toan exposure apparatus that transfers a circuit pattern onto a glassplate or silicon wafer to produce a mask or reticle used in a lightexposure apparatus, an EUV exposure apparatus, an X-ray exposureapparatus, an electron-beam exposure apparatus, and the like.

Electronic devices such as semiconductor devices are manufacturedthrough the steps of; a step where the function/performance design ofthe device is performed, a step where a reticle based on the design stepis manufactured, a step where a wafer is manufactured from siliconmaterials, a lithography step where the pattern of a reticle istransferred onto the wafer by the exposure apparatus (pattern formationapparatus) in each of the embodiments above, a development step wherethe wafer that has been exposed is developed, an etching step where anexposed member of an area other than the area where the resist remainsis removed by etching, a resist removing step where the resist that isno longer necessary when etching has been completed is removed, a deviceassembly step (including a dicing process, a bonding process, thepackage process), inspection steps and the like. In this case, in thelithography step, because the device pattern is formed on the wafer byexecuting the exposure method previously described using the exposureapparatus in each of the embodiments above, a highly integrated devicecan be produced with good productivity.

While the above-described embodiments of the present invention are thepresently preferred embodiments thereof, those skilled in the art oflithography systems will readily recognize that numerous additions,modifications, and substitutions may be made to the above-describedembodiments without departing from the spirit and scope thereof. It isintended that all such modifications, additions, and substitutions fallwithin the scope of the present invention, which is best defined by theclaims appended below.

What is claimed is:
 1. An exposure apparatus that exposes a substratewith an illumination light via a projection optical system and a liquid,the apparatus comprising: a mask stage system having a first stage and afirst drive system, the first stage being disposed above the projectionoptical system and holding a mask illuminated with the illuminationlight, and the first drive system having a motor configured to drive thefirst stage; a nozzle member provided to surround a lens that isdisposed closest to an image plane side, of a plurality of opticalelements of the projection optical system, the nozzle member having alower surface that is disposed lower than an emitting surface of thelens and forming a liquid immersion area with the liquid under the lens;a base member disposed below the nozzle member; a substrate stage systemhaving two second stages and a second drive system, the two secondstages being disposed on the base member and each holding a substrate,and the second drive system having a planar motor configured to drivethe two second stages; and a controller coupled to the mask stage systemand the substrate stage system, the controller controlling the first andthe second drive systems so that scanning exposure in which the mask andthe substrate are each moved relative to the illumination light isperformed with a first direction within a predetermined plane serving asa scanning direction, and the predetermined plane being orthogonal to anoptical axis of the projection optical system, wherein a cable isconnected to one second stage of the two second stages from one side ina second direction and another cable is connected to an other secondstage of the two second stages from an other side in the seconddirection, the second direction being orthogonal to the first directionwithin the predetermined plane, and wherein the controller: controls thesecond drive system so that the other second stage comes close to theone second stage placed facing the projection optical system from oneside in the first direction, and the two second stages that have comeclose together are moved from the one side to another side in the firstdirection, in order to place the other second stage to face theprojection optical system instead of the one second stage whilesubstantially maintaining the liquid immersion area under the lens,controls the second drive system so that the one second stage, that islocated on the other side in the first direction with respect to theother second stage placed facing the projection optical system, is movedto an exchange position of the substrate, by passing the one side in thesecond direction with respect to the other second stage, the exchangeposition being set on the one side in the first direction with respectto the projection optical system, controls the second drive system sothat the one second stage comes close to the other second stage placedfacing the projection optical system from the one side in the firstdirection, and the two second stages that have come close together aremoved from the one side to the other side in the first direction, inorder to place the one second stage to face the projection opticalsystem instead of the other second stage while substantially maintainingthe liquid immersion area under the lens, and controls the second drivesystem so that the other second stage, that is located on the other sidein the first direction with respect to the one second stage placedfacing the projection optical system, is moved to the exchange position,by passing the other side in the second direction with respect to theone second stage.
 2. The exposure apparatus according to claim 1,wherein each of the two second stages has a measurement member thatdetects the illumination light via the projection optical system and theliquid of the liquid immersion area, and the controller controls thesecond drive system so that a detection operation of the illuminationlight by the measurement member is performed prior to the scanningexposure.
 3. The exposure apparatus according to claim 2, wherein themeasurement member includes an aerial image measurement device thatdetects an image via a slit pattern disposed on an upper surface of thesecond stage, the image being projected via the projection opticalsystem and the liquid of the liquid immersion area, and the slit patternis disposed on the other side in the first direction on the uppersurface of the second stage.
 4. The exposure apparatus according toclaim 3, further comprising: a mark detection system that is disposed onthe one side in the first direction with respect to the projectionoptical system, spaced apart from the projection optical system, andthat detects a mark of the substrate, wherein the controller controlsthe second drive system so that: a detection operation of the mark isperformed with respect to each of the two second stages in a measurementstation in which the mark detection system is disposed; each of the twosecond stages is moved from the measurement station to an exposurestation in which the projection optical system is disposed, and anexposure operation of the substrate is performed with respect to each ofthe two second stages; and each of the two second stages is moved fromthe exposure station to the measurement station and an exchangeoperation of the substrate is performed at the exchange position.
 5. Theexposure apparatus according to claim 4, wherein exchange of a substrateheld by the one second stage is performed at a first exchange positionin the measurement station, and exchange of a substrate held by theother second stage is performed at a second exchange position that isdisposed on the other side in the second direction with respect to thefirst exchange position, spaced apart from the first exchange positionin the measurement station.
 6. The exposure apparatus according to claim1, wherein the controller controls the second drive system so that inmovement of the two second stages that have come close together, the twosecond stages are placed shifted in the second direction.
 7. Theexposure apparatus according to claim 6, wherein in a first replacementoperation of placing the other second stage to face the projectionoptical system instead of the one second stage by the movement of thetwo second stages that have come close together, the other second stageis placed shifted to the other side in the second direction with respectto the one second stage, and in a second replacement operation ofplacing the one second stage to face the projection optical systeminstead of the other second stage by the movement of the two secondstages that have come close together, the one second stage is placedshifted to the one side in the second direction with respect to theother second stage.
 8. The exposure apparatus according to claim 7,wherein in the first replacement operation, the one second stage isplaced shifted to the one side in the second direction with respect tothe nozzle member, and in the second replacement operation, the othersecond stage is placed shifted to the other side in the second directionwith respect to the nozzle member.
 9. The exposure apparatus accordingto claim 8, further comprising: a frame member that supports theprojection optical system; and an encoder system that has a plurality ofheads provided at each of the two second stages and irradiatesreflective gratings of a plurality of scale members from below withmeasurement beams via the plurality of heads, the plurality of scalemembers being supported by the frame member to be substantially parallelto the predetermined plane, wherein at least in an exposure operation ofthe substrate, positional information of the two second stages ismeasured with the encoder system.
 10. A device manufacturing method,comprising: exposing a substrate by the exposure apparatus according toclaim 1; and developing the substrate that has been exposed.
 11. Anexposure method of exposing a substrate with an illumination light via aprojection optical system and a liquid, the method comprising: holding amask with a first stage disposed above the projection optical system;placing one second stage of two second stages to face the projectionoptical system, on a base member disposed below a nozzle member, thenozzle member being provided to surround a lens that is disposed closestto an image plane side, of a plurality of optical elements of theprojection optical system, the nozzle member having a lower surface thatis disposed lower than an emitting surface of the lens and forming aliquid immersion area with the liquid under the lens, and the two secondstages each holding a substrate and being moved by a planar motor;moving the first stage and the one second stage so that scanningexposure in which the mask and the substrate are each moved relative tothe illumination light is performed with a first direction within apredetermined plane serving as a scanning direction, the predeterminedplane being orthogonal to an optical axis of the projection opticalsystem; moving an other second stage of the two seconds stages to comeclose to the one second stage placed facing the projection opticalsystem from one side in the first direction, a cable being connected tothe one second stage from one side in a second direction and anothercable being connected to the other second stage from an other side inthe second direction, and the second direction being orthogonal to thefirst direction within the predetermined plane; moving the two secondstages that have come close together from the one side to an other sidein the first direction, in order to place the other second stage to facethe projection optical system instead of the one second stage whilesubstantially maintaining the liquid immersion area under the lens;moving the one second stage, that is located on the other side in thefirst direction with respect to the other second stage placed facing theprojection optical system, to an exchange position of the substrate, bymaking the one second stage pass the one side in the second directionwith respect to the other second stage, the exchange position being seton the one side in the first direction with respect to the projectionoptical system; moving the one second stage to come close to the othersecond stage placed facing the projection optical system from the oneside in the first direction; moving the two second stages that have comeclose together from the one side to the other side in the firstdirection, in order to place the one second stage to face the projectionoptical system instead of the other second stage while substantiallymaintaining the liquid immersion area under the lens; and moving theother second stage, that is located on the other side in the firstdirection with respect to the one second stage placed facing theprojection optical system, to the exchange position, by making the othersecond stage pass the other side in the second direction with respect tothe one second stage.
 12. The exposure method according to claim 11,wherein each of the two second stages has a measurement member thatdetects the illumination light via the projection optical system and theliquid of the liquid immersion area, and each of the two second stagesis moved so that a detection operation of the illumination light by themeasurement member is performed prior to the scanning exposure.
 13. Theexposure method according to claim 12, wherein the measurement memberincludes an aerial image measurement device that detects an image via aslit pattern disposed on an upper surface of the second stage, the imagebeing projected via the projection optical system and the liquid of theliquid immersion area, and the slit pattern is disposed on the otherside in the first direction on the upper surface of the second stage.14. The exposure method according to claim 13, wherein a mark of thesubstrate is detected with a mark detection system that is disposed onthe one side in the first direction with respect to the projectionoptical system, spaced apart from the projection optical system, andeach of the two second stages is moved from a measurement station inwhich the mark detection system is disposed to an exposure station inwhich the projection optical system is disposed, and is also moved fromthe exposure station to the measurement station, and an exchangeoperation of the substrate is performed in the measurement station. 15.The exposure method according to claim 14, wherein exchange of asubstrate held by the one second stage is performed at a first exchangeposition in the measurement station, and exchange of a substrate held bythe other second stage is performed at a second exchange position thatis disposed on the other side in the second direction with respect tothe first exchange position, spaced apart from the first exchangeposition in the measurement station.
 16. The exposure method accordingto claim 11, wherein in movement of the two second stages that have comeclose together, the two second stages are placed shifted in the seconddirection.
 17. The exposure method according to claim 16, wherein in afirst replacement operation of placing the other second stage to facethe projection optical system instead of the one second stage by themovement of the two second stages that have come close together, theother second stage is placed shifted to the other side in the seconddirection with respect to the one second stage, and in a secondreplacement operation of placing the one second stage to face theprojection optical system instead of the other second stage by themovement of the two second stages that have come close together, the onesecond stage is placed shifted to the one side in the second directionwith respect to the other second stage.
 18. The exposure methodaccording to claim 17, wherein in the first replacement operation, theone second stage is placed shifted to the one side in the seconddirection with respect to the nozzle member, and in the secondreplacement operation, the other second stage is placed shifted to theother side in the second direction with respect to the nozzle member.19. The exposure method according to claim 18, wherein at least in anexposure operation of the substrate, positional information of the twosecond stages is measured with an encoder system that has a plurality ofheads provided at each of the two second stages and irradiatesreflective gratings of a plurality of scale members from below withmeasurement beams via the plurality of heads, the plurality of scalemembers being supported by a frame member to be substantially parallelto the predetermined plane, and the frame member supporting theprojection optical system.
 20. A device manufacturing method,comprising: exposing a substrate by the exposure method according toclaim 11; and developing the substrate that has been exposed.
 21. Amaking method of an exposure apparatus that exposes a substrate with anillumination light via a projection optical system and a liquid, themethod comprising: providing a mask stage system having a first stageand a first drive system, the first stage being disposed above theprojection optical system and holding a mask illuminated with theillumination light, and the first drive system having a motor configuredto drive the first stage; providing a nozzle member to surround a lensthat is disposed closest to an image plane side, of a plurality ofoptical elements of the projection optical system, the nozzle memberhaving a lower surface that is disposed lower than an emitting surfaceof the lens and forming a liquid immersion area with the liquid underthe lens; providing a base member disposed below the nozzle member;providing a substrate stage system having two second stages and a seconddrive system, the two second stages being disposed on the base memberand each holding a substrate, and the second drive system having aplanar motor configured to drive the two second stages; and providing acontroller coupled to the mask stage system and the substrate stagesystem, the controller controlling the first and the second drivesystems so that scanning exposure in which the mask and the substrateare each moved relative to the illumination light is performed with afirst direction within a predetermined plane serving as a scanningdirection, and the predetermined plane being orthogonal to an opticalaxis of the projection optical system, wherein a cable is connected toone second stage of the two second stages from one side in a seconddirection and another cable is connected to an other second stage of thetwo second stages from an other side in the second direction, the seconddirection being orthogonal to the first direction within thepredetermined plane, and wherein the controller: controls the seconddrive system so that the other second stage comes close to the onesecond stage placed facing the projection optical system from one sidein the first direction, and the two second stages that have come closetogether are moved from the one side to an other side in the firstdirection, in order to place the other second stage to face theprojection optical system instead of the one second stage whilesubstantially maintaining the liquid immersion area under the lens,controls the second drive system so that the one second stage, that islocated on the other side in the first direction with respect to theother second stage placed facing the projection optical system, is movedto an exchange position of the substrate, by passing the one side in thesecond direction with respect to the other second stage, the exchangeposition being set on the one side in the first direction with respectto the projection optical system, controls the second drive system sothat the one second stage comes close to the other second stage placedfacing the projection optical system from the one side in the firstdirection, and the two second stages that have come close together aremoved from the one side to the other side in the first direction, inorder to place the one second stage to face the projection opticalsystem instead of the other second stage while substantially maintainingthe liquid immersion area under the lens, and controls the second drivesystem so that the other second stage, that is located on the other sidein the first direction with respect to the one second stage placedfacing the projection optical system, is moved to the exchange position,by passing the other side in the second direction with respect to theone second stage.